BACKGROUND: Trichomoniasis is associated with adverse pregnancy outcomes and increased risk for human immunodeficiency virus. Males are usually asymptomatic, and thus there is heavy reliance on partner notification for identifying infected male partners. The usual approach is partner referral but it is estimated that only a minority of men seek care. We conducted a randomized trial to compare the effectiveness of 3 methods of partner notification. METHODS: Women were randomized to self-referral of partners (PR), partner-delivered therapy (PDPT), or public health disease intervention (DIS) locating partners and delivering medication in the field, if needed. Test-of-cure visits were conducted at 5 to 9 days after enrollment. Repeat infections at 1 and 3 months of follow-up were the measure of effectiveness. RESULTS: A total of 484 women were randomized. Initial cure rates were 95.3%. At the 1-and 3-month follow-up visits, there was no significant difference in repeat infection rates when PDPT or DIS were compared to the reference of PR. However, when PDPT was compared to DIS or PR/DIS combined, at 1 month the PDPT group had a lower repeat infection rate (5.8 vs. 15% and 5.8 vs. 12.5%, respectively). Of these, 80% of women randomized to PDPT reported delivering medication and 89% thought it likely that partners took the medication. No serious adverse events were reported. CONCLUSIONS: PDPT for trichomoniasis was well accepted and safe in this study. Rates of repeat infection in women in this intervention were lower than those in the DIS arm and DIS/PR arm combined although when compared directly to PR there was no significant difference. Copyright © 2010 American Sexually Transmitted Diseases Association.