In a word: Absolutely. When speaking of ATV helmets to wear one or not shouldn't even be a question. That is, unless you think things like recovering from head injuries, facial lacerations and perhaps even losing your life sound like a good time to you. Not to mention, there's a very good chance wearing a helmet while operating an ATV is probably state law where you live and not wearing one will result in a fine.
ATV helmets can not only save your life, they will lessen the noise from the wind and when your hearing is better making your ride a lot safer. Also, a good full-face helmet is great protection against flying insects and other flying debris that gets kicked up when you ride. And let's face it, a bug in the face or dirt in your eyes is going to be a definite hindrance to maneuvering your ATV.
A lot of folks don't like to wear ATV helmets because they feel they are too tight. That's because they are supposed to feel tight. A properly fitted helmet conforms to your head, you don't want any wiggle room in there. If you did suffer an impact and there is room inside your helmet, your head will slam to one side and your brain will continue traveling inside your skull in the same direction with the same velocity. If this happens to you, you will most certainly have more than a headache at the very least and most likely a concussion. Hence, a good fitting ATV helmet will indeed feel tight when you first put it on but that is the intelligence of its very design.
No matter how good, helmets wear out. You need to replace your helmet every 4-5 years as the glues, resins and other materials the helmets are made out of will deteriorate with time. Helmets are good for one impact only. If you have suffered an impact while wearing your helmet, and even if you don't see any cracks or damage, replace that helmet before you go riding again. The integrity of the helmet has been compromised and you shouldn't rely on it for safety. Helmets are a definite must for the ATV rider and they should always be worn. If you need a helmet or need to upgrade your helmet, check out the enormous selection at Raceway and as always, shipping is free!