Yes, Obi Wan was killed. In the act of dying at the hands of Darth Vader, his body disintegrated. However, in dying, he became part of the Force and had the ability to return in spirit to communicate at least with Luke and Yoda. ****************** "punji73: ok, if old ben and yoda's body dissolved how come quay gon's body didnt dissolve? could it be a newly learnt jedi technique?" As we learned in Episode 3 and is made a bit more clear in the novel based on that movie, this is a new technique. They learned it from the ghost of Qui Gon. I would say that the reason Qui Gon's body didn't disappear when he died is because he did not fully master it until after his death. The book left me with the impression that Qui Gon only started directly communicating with Yoda within the time period of Episode 3. This was about thirteen years after his death. Obi-wan and Yoda were able to communicate with Luke within days of their deaths (if not sooner). This, to me, indicates a greater mastery of the discipline. So, Qui Gon's body didn't disappear because he didn't fully mastered the technique until after his death. However, once he had mastered it, he was able to pass that knowledge onto Yoda and Obi-Wan so that they were able to fully merge with the Force at the times of their deaths. Thus their bodies did disappear.

He was killed in Star Wars back in 1977. His body became blue in Return of the Jedi, which I guess made him like a spirit. I hope this helps!

No one knows for certain. "Luminous beings are we, not this crude matter," Yoda told Luke—but did anyone ever tell Obi-Wan? Take any recording of Return of the Jedi, put it in the appropriate player, and look at Luke's conversation with Obi-Wan Kenobi after Yoda's death. Watch carefully, starting with Obi-Wan's approach through the jungle. You will notice two things. First, he seems to interact physically with the objects around him, as if his "luminous being" still possessed some of his "crude matter." He quite plainly moves vines out of his way as he enters the clearing; he is equally plainly walking; and, when he stops, he sits down on the log where he and Luke have their heart-to-heart about what really happened to Luke's father. Second, as Obi-Wan takes his seat, he casts a shadow. Look carefully at the tree roots and brush behind him, at the upper right of the screen, an unmistakable shadow tracks his movements, his shadow. Very un-spirit-like, that, yet there it is. Why should this be? An examination of Obi-Wan's postmortem existence may prove enlightening. Let's begin at the beginning, with Obi-Wan's apparent death (he vanished: he has always been presumed to have died, but all we can be certain of is that he disappeared, dematerialized) on the first Death Star. Vader's lightsaber came round, aimed to slice the old man in two; the old man's slashed robe fell to the floor, empty: old Obi-Wan was nowhere to be seen. Within seconds, Obi-Wan's voice, disembodied, commanded Luke to "Run!" -- this was his first manifestation. He manifested twice more in A New Hope, telling Luke to use the Force, and that it would be with him, always. Both times, it was voice only, hollow, eerie. In The Empire Strikes Back, Obi-Wan returns, adding sight to sound, appearing in the wastes of Hoth to order Luke to Dagobah. The voice is much the same as in the previous film: a distant, spectral echo from another plane of existence. In this first visual manifestation, Kenobi appears monochromatic, almost static, an image projected on a screen -- in a word: remote. Apart from a brief audio-only exchange with Yoda on Dagobah, he does not manifest again until Luke prepares to depart for Bespin to rescue his friends. When he does, the Obi-Wan we see is much different from the one we saw in the wintry wastes of Hoth. He has an active, coruscating blue aura, but is not monochrome. Though more dimensional, and more active, he seems frail. While he appears in the clearing, he does not seem to interact with the clearing, or anything in it. Indeed, he is not even in contact with it, his image fades out before reaching the jungle floor: he floats. Obi-Wan does not manifest again until his conversation with Luke in Jedi. As noted, he appears to be more than a mere apparition or spectral presence, interacting with physical objects, moving in space as a living, breathing three dimensional being might -- drastic changes from his behavior in The Empire Strikes Back. But the differences don't end there. Obi-Wan's aura is less pronounced, less active, a gentle nimbus outlining his form. Obi-Wan looks more robust. He seems, to have become much less spectral, much more physical. His last manifestation is as part of the trinity on Endor, appearing to Luke with Yoda and Anakin during the Ewok celebration. All appear as Obi-Wan did on Dagobah. Yoda is resting on a railing; Obi-Wan reaches out and touches Yoda. They seem more than mere projections. So, we have an individual who has dematerialized, ostensibly dying and entering a Jedi afterlife, or, as it's called in Star Wars: The Annotated Screenplays, "the Netherworld." But, in his time in this "Netherworld," he has progressed from disembodied voice, to spectral image, to an apparition that ever more closely resembles and emulates its owner's body in life. This looks less like an afterlife than an unfolding process of rematerialization. (A process that accelerated over time, judging from the time lapsed between the observed stages of metamorphosis.) Laurent Bouzereau's Star Wars: The Annotated Screenplays (New York: Ballantine Books, Del Rey, 1997), citing original materials from LFL and interviews with the writers, directors and others, including Lucas himself, offers a basis for this interpretation. Citing the rough draft of the script for what became The Empire Strikes Back, Bouzereau writes: "In the first draft, during his training Luke calls Obi-Wan Kenobi; Ben appears and explains what has happened to him since he was struck by Vader. He is now in a different part of the Universe. Ben says he's brought someone else with him, and Luke's father appears (obviously in this draft Vader is not Luke's father)...." (p. 182, emphasis added.) "In a different part of the Universe" seems like an awful long way round to say "dead," especially since he goes on to describe how "Skywalker," Luke's father, was there, too, with Luke's sister, whom, it was to be suggested, was being trained and would be a Jedi along side Luke in episodes to come: The Skywalkers certainly don't sound dead. It seems the seriousness of Obi-Wan's demise had been greatly exaggerated. Or perhaps that it had been over-emphasized. Bouzereau relates that Obi-Wan's death came about not because of any great necessity, nor from any requirement of the Grand Design: Lucas is quoted as saying that he found that there was nothing for Obi-Wan to do after the Death Star escape, so he terminated him in the name of narrative economy. And even then, said Lucas, "I knew that I would have to bring him back somehow if I made the other movies, and at the time of Star Wars I didn't know how I was going to accomplish that." (p.82) But, certainly, in its final form, The Empire Strikes Back portrays Obi-Wan as, in the words of Irvin Kershner, "still alive but not corporeal." Indeed. However, George Lucas is nothing if not tenacious. The idea of Obi-Wan's continued, or resumed, corporeal existence was alive and well during the writing of Return of the Jedi. Bouzereau writes that in Jedi's revised rough draft, "He [Luke] suddenly becomes aware of a presence behind him; he looks back and sees Ben in the flesh." (p. 301, emphasis added.) He had returned to help Luke defeat Vader and the Emperor. Ben was still flesh-and-blood at the end of the script in that draft, and was rejoined in the land of the living by Yoda, and even Anakin. Now, does this mean that Obi-Wan was portrayed deliberately as rematerializing in the Original Trilogy? Lucas killed Obi-Wan off prematurely. He immediately brought him back, and sought to undo his death in each of the two remaining Original Trilogy films. In the course of these the ostensibly dead Obi-Wan appears to be getting livelier all the time. Can this be coincidence? Are the gradual changes in Obi-Wan's apparent condition merely artifacts of differences among effects shots for the blue aura sequences in the Original Trilogy films? Nine was the number of films most often referred to at the time the Original Trilogy was completed, which implies three more films after Jedi: Was it in Lucas's mind to finish Obi-Wan's gradual resurrection? Perhaps the answer's been revealed somewhere in the commentaries on the OT DVDs, or in some other source this spoiler-averse writer has avoided. Perhaps only Lucas himself knows. But, based upon the annotated screenplays and the Original Trilogy films themselves, it is no great leap to assume that, at the rate Obi-Wan was regaining corporeal characteristics, the trend, projected into another trilogy, pointed to only one thing: Obi-Wan resurrected. And I will prophesy you this: If in the years ahead more episodes are forthcoming, Obi-Wan's resurrection, like so many other ideas Lucas has shelved over the years, will return, and bear fruit. http://www.echostation.com/features/shadow_of_the_jedi.htm

Obi Wan was killed by Vader but he let it happen. Go back and listen to what he says "If u strike me down I will be more powerful than you ever imagined" So basically he told Vader kill me and u killing me will be your downfall.

No. He returned to the force to inspire Luke. If he had been killed Obi-Wan than Obi-Wan's body would have fallen dead to the ground, just like when Qui-Gon was killed by Darth Maul.