"It can be very helpful in preventing and treating a urinary tract infection. It works by preventing bacteria from sticking to the walls of the bladder where it can multiply and cause infection. Cranberry juice acts like a natural antibiotic to the urinary system. Not all juices do this....but cranberry juice and blueberry juice are two that do."

Why Cranberry Juice Works

"Although promising for anti-bacterial activity, long-term consumption of cranberry juice has not been adequately proven to reduce urinary tract infections. However, there is preliminary evidence for possible effects against urinary tract infections in women. It is thought that cranberry proanthocyanidins are responsible for the apparent efficacy of consuming cranberry juice against urinary tract infections. Their mechanism of action may be related to inhibition of adherence of Escherichia coli to urothelial cells."

From the wiki article on cranberries. So while it's not necessarily a foolproof method of preventing/reducing urinary tract infections it certainly can't hurt (and consuming cranberry juice may also help with providing essential vitamins/minerals, as well as antixodidants).

It works for me. I drink UNSWEETENED, 100% cranberry juice mixed with UNSWEETENED tea (I mix the blend of tea myself and it's always changing) and I have not had a UTI since drinking this mix (about 3 years). The key here is unsweetened. If you drink the shit juice they commonly sell at most stores (mixed with grape, usually sweetened), you just start ingesting a ton of sugar which has it's own problems.

thanks, i was also wondering!

Balanced diet and fluid consumption, mostly, has helped in my case. The main thing is not upsetting the pH in the system. I found this out the hard way after consuming nothing but soda over a birthday weekend. XP

I do suspect it's all individual - some are more susceptible to UTI's than others.