UTIs are a common problem among young women, resulting in considerable morbidity and health care costs. Increasing resistance to antibiotics is making treatment of these infections even more problematic. Therefore, safe and effective nonantimicrobial prevention strategies are needed. One approach that appears to be effective is the use of cranberry products. However, data on the safety and effectiveness of cranberry products are limited. This study will determine whether cranberry juice can reduce UTIs in women.