When it comes to Star Trek, you can often find holes big enough to fly a starship through. But by far, the most glaring of all gaffes happened in the movie "The Wrath of Kahn." Chekov and the Captain of the USS Reliant beam down to planet Ceti Alpha 5, and to their shock find cargo bins. They go inside them to investigate, only to be ambushed by Kahn and his clan. Kahn removes his mask, walks up to the Captain, and says: "I don't know you." Then he looks Chekov right in the eye and says: "But you...I never forget a face. You are...Chekov." Nice try, but this movie was based on the television episode "Space Seed", from the first season. Pavel Chekov wasn't in that episode. In fact, his character wasn't written into the cast until many episodes later!

If you mean plot wise, I agree with the answer regarding The Wrath of Kahn. If you mean timeline wise, I propose the following: In the movie "Generations" we learn that Kirk supposedly dies on a rescue mission. Scotty was there to witness this. In the STNG episode "Relics", Scotty was on a ship traveling to his place of retirment when they encountered a Dyson Sphere (essentially an artifical construct built completely around a star at a distance capable of supporting life on the inside of the shell). Scotty was able to save his life by using the transporters to hold his signature in a diagnostic pattern buffer until he could be rescued. The Enterprise-D found the wreckage and pulled Scotty out. Scotty asked what ship they were from, Riker said "The Enterprise." Scotty's reply: "The Enterprise! I bet Kirk pulled her out of mothballs to rescue me himself." Scotty should have known by this point that Kirk was dead. A glaring "goof." Of course, you could say that he was disoriented... To John Brunno: You almost have a good point. Given the sensor systems and in ship-monitoring systems (such as cameras - refer to previous Star Trek movies such as III: The Search for Spock), the equipment of the ship and sensor logs would have shown, from the bridge or any computer terminal, that Kirk was blown out and his life signs disappeared. According to scientific equipment and camera records, Scotty would have had the oportunity to observe this event from any angle given the seriousness of the deflector control array (how it clears the path for the ship at warp speed would be a high security area). No doubt, a lifetime friend would have wanted to see for his own eyes to be sure how his friend was lost. Scientifically and according to records - to all of mankind and the recorded data, Kirk was dead. From a "fixed time perspective," Kirk died and it is only in a temporal sense that Kirk did not as the Nexus exists both inside and outside of the space-time continuum. Also, Kirk's reappearance did not happen by the time of Scotty's rescue from the Dyson Sphere so the Star Fleet records would still have shown Kirk to be deceased, so Kirk being caught in the Nexus and deposited in the future would have had no bearing on Scotty's response as it would not have happened yet therefore the plot contradiction still stands!

Seeing a Klingon on Earth on the first Enterprise episode. Jean-Luc Picard mentioned on a TNG episodes that a bad "First Contact" with Klingons led to years of conflict and war with them (hence TOS episodes). Jean-Luc's comment led you to believe that Humans made first contact with Klingons and were technologically more advanced than them.

The Star Trek timeline has been so heavily modified and "retconned" so many times, that it is difficult to identify one major goof. In fact, perhaps the biggest goof has been the tendency to tinker with the timeline over and over again, as happened in the last series, "Enterprise". In an attempt to pander to fans, old characters and adversaries (like the Borg) have been brought back repeatedly in new time travel situations, that would wreak havoc on the space-time continuum. For the sake of continuity, it would have been better to leave past events untouched.

In conjunction with this is that in a Deep Space Nine episode Kirk is said to be alive. The episode involved a parallel universe, in which there is an evil Kira. A DS9 character crossed over and tried to change the evil there. The evil Kira tells the DS9 character that James Kirk got crossed over into this universe too and also, unsucessfully, tried to change the evil.

The biggest goofs are in the original series. The biggest of them all was SO bad, I know they later went back and fixed it, but this is it as it was originally broadcast, which will probably be new news to all you super-star-trek-nerds: I don't know the name of the episode, but it was the episode were there was an invisible assassin on board, I believe, and Spock had rigged a device to amplify sound so that when the noises made by everyone and everything who and that were authorized to be there was accounted for and was subtracted off, what was be left would the sound of the heartbeat of the invisible assassin. And as Spock originally described the sound-amplifier, he said it would "boost all sounds by a factor of one to the tenth power". That's not a very big gain. You don't need any special device to do it! You see, I have all these tapes that were recorded 25 years ago when they were being shown as reruns on some broadcast network, when my aunt recorded them, and apparently the gross problems hadn't been fixed, so I get to see them as they originally were. Here's one that I don't know if it was taken out. It was the episode where Spock and a few others get stranded in their craft on some planet, and a redshirt gets speared by a hairy-ape man of some sort, and they only had enough fuel to get their shuttlecraft so high, and the plan was that hopefully the enterprise would detect them and beam them out. I think. Anyway, Spock says something along the lines of "if we don't survive long enough to get into orbit, we will surely die". Some such sort of Goldwynism.

According to computer records, the best selection of errors, or goofs if you prefer, have already been presented. To expound on them further would be most illogical.

For me, the biggest would have to be the way the warp factors were reconfigured from what they were in the original series to what they were in TNG forward. Second would have to be when Wesley Crusher (TNG) takes a test at Starfleet Academy where he has to configure the matter to antimatter ratios in a mock warp core. The ratio would necessarily always have to be 1:1 for matter-antimatter reactions, so the very test is nonsense. The thing with Star Trek is that even though it has some wonderful science, it often neglects to maintain it consistently throughout, in favor of the story line. It also excels at using very interesting sounding pseudo-scientific jargon that holds only minimal relevance to anything other than, again, the story line. I enjoy watching it, even Enterprise, but it can get a little annoying at times because my "suspension of disbelief" is easily broken when it hits inconsistencies.

The ST:TNG Episode "Relics" also has a goof regarding how Geordi and Scotty are beemed back onto the Enterprise. The two wedge the Jenolen in the hatch of the Dyson sphere and the Enterprise has to blow it up to escape through hatch. Picard orders the two transported aboard, but you can clearly see the shields are still up on the Jenolen when the two are transported. This should not be possible.

I will make this quick and easy.the biggest goof of all time has to be the klingons.In TOS they are completly different looking/acting then the movies or any of the other series.Not to mention the fact that the newer klingons would have been destroyed a long time ago either by themselves or others just based on there foreign policy regarding other cultures

People In Star Trek never seem to take a crap. In fact, I have never seen anything resembling a toilet anywhere in Star Trek, not even a door with any symbol on it hinting at such device beyond.

It's cancellation.

The fact that it was ever made in the first place?

Introducing the beam: that defies all kind of logic and has caused harm to the quality of future episodes.

In the Star Trek world, they say money does not exist. I think the first reference to this is in Star Trek IV. Yet, in Generations, Kirk states that he SOLD his cabin years ago. In Star Trek VI, Scotty says he just BOUGHT a boat. There are other references to buying and selling things.. Like in Mudd's Women.. The Federation Lithium Miners are described as "rich." In Star Trek III, McCoy's "backwards friend" wants "money more" to take them to Genesis. Those are the ones that come to mind but I'm sure there's more.

Don't bother McCoy while he's smoking... http://www.youtube.com/watch?v=JuIxiBPMuqU

I have a personal hatred when characters are re-used. In Star Trek, several characters were re-used over and over Like Troi's Mum who was a nurse in the Original Series. But the one i hate most of all is Tuvok who played a major Vulcan character in Voyager but was also a Human Helmsman on board the Enterprise C in one of the films, although i forget the name, maybe generations

Data goofed when he deactivated his emotion chip.

In "Relics," Geordi states that Scotty's transporter pattern suffered less than 1% degradation. Obviously, Scotty's memory of Kirk's death was in that percentage. Also, concerning money, Starfleet and the Federation do not seem to use money but some worlds outside the UFP do, hence the characters talking about using money.

I get a bit peeved at the excessive use of Cordrizine and Inaproveline on Voyager. These two drugs cant possibly cure EVERYTHING. They use the same drug to put someone to sleep and wake them up it seems

When Kirk left the green girl on her planet...