According to technology experts at Ars Technica, iPod devices do not feature a waterproof case. Since iPods do not have waterproof cases, water from the washing machine may damage sensitive electronic components inside the device. Repeated tumbling and high heat in a clothes dryer may also damage or break the liquid crystal display (LCD) screens found on most iPod models.

On the Other: iPods Have Survived Washing and Drying

Although the manufacturer does not recommend exposing iPods to water, Ars Technica has documented at least one case of an iPod device returning to normal operation after being washed in a washing machine and dried in a dryer. In this particular case, a user allowed the washed iPod to dry completely before plugging it in and charging the discharged battery.

Bottom Line

Although the manufacturer does not recommend exposing iPods to water, at least one documented case indicates that iPods may survive a trip through a washing machine and dryer. The ability of the device to operate after such exposure, though, depends on how much water penetrates the device's case, how much damage the device sustains in the dryer and how thoroughly the device dries before being placed back in operation.

Source:

Ars Technica: iPod nano vs washing machine?

Wired.com: iPod Nano versus washing machine

Apple Support: iPod Frequently Asked Questions