To determine the rate of occurrence of Gardnerella vaginalis in the genital tract and rectum of the asymptomatic prepubertal boy and to examine the effect of circumcision on the rate of recovery. Design: A prospective survey design was used. Cultures for G vaginalis were obtained from the urethral meatus, surrounding glans, and rectum of prepubertal boys. Boys who had a history of sexual abuse, current urogenital symptoms, or who had taken antibiotics in the preceding 2 weeks were excluded from this study. Setting: The study was conducted in ambulatory clinical settings at a children's hospital within a major medical center that serves as a statewide referral center. Participants: A group of 99 circumcised and uncircumcised prepubertal boys participated in the study. The participants ranged in age from 1 month to 7 years 4 months. Main Outcome Measure: Results of cultures for G vaginalis. Results: No cultures were positive for G vaginalis from the urethra, glans, or rectum in any of the participants in this study. Conclusions: The findings of this study provide preliminary evidence that G vaginalis is not an organism that commonly colonizes the urogenital or gastrointestinal tract in asymptomatic prepubertal boys. Based on these findings, it does not seem prudent to apply the concept of asymptomatic colonization to prepubertal boys unless further studies refute these findings.