Trichomonas vaginalis is the most prevalent, non-viral sexually transmitted infection worldwide and probably the most commonly treatable in Africa and worldwide. The purpose of this study was to determine the prevalence of T. vaginalis among women with vaginal discharge attending a gynaecologic clinic in Lagos and to identify the common characteristics of the vaginal discharge in T Vaginalis. High vaginal swabs were taken from consenting adults with vaginal discharge. The quantity, colour and odour of the discharge were noted. Amine (10% KOH) test and pH were determined. Wet-mount microscopy Giemsa staining and culture in Oxoid (R) Trichomonas Medium were performed on each swab. A total of 200 patients were examined. One hundred and forty-nine (74.5%) had T. vaginalis. There was no statistically significant association between age, marital status, parity, number of sexual partners and prevalence of T vaginalis. The colour of the discharge was white in 104 (69.8%), yellow in 30 (20.1), clear in 15 (10.1%). None was frothy or greenish. The discharge was heavy in 50 (33.6%) and malodorous in 51 (34.2%). The pH range was 4-7 and 42 (28.2%) normal pH of4. In 47 (31.5%) the amine test was negative. The prevalence of T vaginalis among women with vaginal discharge is high. Women complaining of vaginal discharge should be thoroughly screened for T. vaginalis using all available methods.