Pocket and All In One Cloth Diapers
Yes. If you have purchased pocket style or all in one type diapers, you should first try your new diapers on your baby to ensure they fit BEFORE washing. If they fit, yes, you should wash the diapers before use on your baby. Pocket or all in one style cloth diapers made with fleece or suede on the inside that come with micro terry or fleece inserts need only be washed once before use.

Bamboo Diapers
If you have purchased diapers that are made in any part with bamboo or come with bamboo liners, you can get away with just one initial wash before use, but be aware that bamboo becomes more absorbent over time and with multiple washings. So if you are getting leaks, be aware that your bamboo may need more washings before reaching maximum absorbency.

Cotton Prefolds
For organic cotton, most often used in prefold type diapers like the Bummis, you will need to do 3-5 pre-washes in hot water before they are ready for use. Since organic cotton is not bleached you will need to do the pre-washes to flush out all the natural oils that would affect proper absorbency if used right away.

Pre-washing your prefolds also helps to bulk them up and puff them up making them nicely quilted and soft. You should expect approximately 25% shrinkage when your pre-washes are complete.

Diaper Covers
Covers do not need to be pre-washed.

NOTE: Pre-washing means washing in a recommended cloth safe detergent AND drying the diapers. In other words, one pre-wash includes a wash and a dry (whether you air dry or dry in the dryer does not matter).