In a double-blind, randomized, controlled trial, efficacy and safety of a single-day split dose of 1.6 g of metronidazole were compared with a single 2-g dose of tinidazole in the treatment of vaginal trichomoniasis. Women with symptomatic vaginal trichomoniasis were randomly assigned to one of the two treatment groups. There were 67 women in the group treated with the single-day split dose and 65 in group treated with the single dose. There was no significant difference between the two groups in terms of clinical characteristics (age, weight, and length of follow-up period). The cure rates, using trypticase yeast extract iron serum (TYI) medium to confirm microbiologic cure, were 98.5% and 100% for the groups treated with a single-day split dose and with a single dose, respectively. The side effects were minimal and did not warrant any treatment. The differences in the results were not statistically significant. We recommend that the single-day split dose of 1.6 g of metronidazole regimen be given as an alternative drug for vaginal trichomoniasis. Its advantages include being highly effective, significantly less expensive, and with minimal side effects.