Objective To evaluate whether single-dose treatments are as effective as standard therapy in the syndromic management of vaginal discharge. Methods A randomized controlled effectiveness trial compared single-dose tinidazole plus fluconazole (TF) with treatment for 7 days with metronidazole plus 3 days of treatment with vaginal clotrimazole (MC) among 1570 women presenting with vaginal discharge at primary health care institutions in Ghana, Guinea, Mali and Togo. Participants were randomly allocated to one of the two treatments by research nurses or physicians using precoded envelopes. Effectiveness was assessed by symptomatic response on day 14. Clinical identifier ClinicalTrials.gov NCT00313131. Findings The two treatment regimens had similar effectiveness: complete resolution was seen in 66% (TF) and 64% (MC) and partial resolution in 33% (TF) and 34% (MC) of participants (P = 0.26). Effectiveness was similar among subgroups with vulvovaginal candidiasis, Trichomonas vaginalis vaginitis or bacterial vaginosis. The two treatment regimens had a similar effectiveness among human immunodeficiency virus (HIV)-infected (TF: n = 76, 71% complete resolution, 28% partial; MC: n = 83, 72% complete resolution, 25% partial, P = 0.76) and HIV-uninfected women (TF: n = 517, 68% complete, 32% partial; MC: n = 466, 65% complete, 33% partial, P = 0.20). Cervical infections with Neisseria gonorrhoeae, Chlamydia trachomatis and Mycoplasma genitalium were uncommon among women not involved in sex work, were associated with bacterial vaginosis or T. vaginalis vaginitis, and did not alter response to treatment with agents active against vaginal infections. Four-fifths of women not relieved by a single dose of TF had a favourable response when MC was administered as second-line treatment. Conclusion Single-dose TF is as effective as multiple-dose MC in the syndromic management of vaginal discharge, even among women with HIV-infection. Given its low price and easier adherence, TF should be considered as a first-line treatment for vaginal discharge syndrome. Voir page 736 le résumé en français. En la página 736 figura un resumen en español.