Vaginal discharge is the most common complaint and Trichomonas vaginalis vaginitis the most frequently diagnosed problem among women attending the DeKalb County Georgia, Veneral Disease Clinic. Despite this prevalence, the 1837 observations of Donné are the criteria frequently used in the clinical and laboratory diagnosis of trichomoniasis. Our study shows that a purulent, frothy discharge is indeed a characteristic of trichomonal vaginitis, but if it is used as the sole diagnostic criterion, 88% of women with trichomonal vaginitis will not be identified and 29% will be erroneously diagnosed as infected. Donné's wet-mount test remains highly specific, but culture will detect twice as many trichomonas infections. There is a positive association between trichomoniasis and gonococcal cervicitis, failure to use contraceptive techniques, and lack of yeast in the wet mount of vaginal secretions.