Because of the high prevalence rate, the bothersome nature of the organism, and its potential for causing serious complications in the pregnant patient, it is essential for all practitioners involved in the health care of women to be able to easily and consistently identify and effectively treat Gardnerella vaginalis vaginitis. Diagnosis should be based upon positive findings in at least three of four of the following clinical criteria: 1) homogenous grey discharge, 2) clue cells on wet smear, 3) vaginal pH greater than 4.7, and 4) a positive potassium hydroxide (KOH) test, rather than any single parameter. Metronidazole 2 g on days 1 and 3 of treatment is recommended for all patients who can take metronidazole. Alternate drug therapy includes ampicillin, tetracycline, cephradine, or cephalexin. Treatment of male sexual partners also is recommended.