Nonspecific vaginitis, one of the most common causes of vaginitis in adults, is a polymicrobial infection in which vaginal anaerobes act synergistically with Gardnerella vaginalis. The diagnosis is made by examination of the vaginal secretions for clue cells, the development of a fishy odor after the addition of 10% KOH to vaginal secretions, and a vaginal pH greater than 4.5. To determine whether nonspecific vaginitis occurs in sexually abused children, we obtained vaginal washes from 31 abused and 23 nonabused children, 21/2 to 13 years of age. A child was considered to have definite nonspecific vaginitis if her wash contained both clue cells and odor; she was considered to have possible nonspecific vaginitis if her wash contained either clue cells or odor. We did not use vaginal pH as a diagnostic criterion because the normal range has not been standardized in prepubertal girls. Possible nonspecific vaginitis (odor only) was found in only 1/23 (4%) of nonabused children. This girl was asymptomatic and findings from her examination were normal. Only one of the 31 abused children had possible nonspecific vaginitis (odor) detected at the initial examination, less than 48 hours after the episode of abuse, whereas 4/31 (13%) developed definite, and 4/31 (13%) possible nonspecific vaginitis at the follow-up visit more than seven days after the episode of abuse or rape. Five of these eight girls developed either a new vaginal discharge or dysuria; three were treated with metronidazole with resolution of their symptoms and reversion of the vaginal wash to normal.(ABSTRACT TRUNCATED AT 250 WORDS)