BACKGROUND: Prevention of mother-to-child transmission of HIV (PMTCT) is a major public health challenge in Zimbabwe. METHODS: Using trained peer counselors, a nevirapine (NVP)-based PMTCT program was implemented as part of routine care in urban antenatal clinics. RESULTS: Between October 2002 and December 2004, a total of 19,279 women presented for antenatal care. Of these, 18,817 (98%) underwent pre-test counseling; 10,513 (56%) accepted HIV testing, of whom 1986 (19%) were HIV-infected. Overall, 9696 (92%) of women collected results and received individual post-test counseling. Only 288 men opted for HIV testing. Of the 1807 HIV-infected women who received posttest counseling, 1387 (77%) collected NVP tablet and 727 (40%) delivered at the clinics. Of the 1986 HIV-infected women, 691 (35%) received NVPsd at onset of labor, and 615 (31%) infants received NVPsd. Of the 727 HIV-infected women who delivered in the clinics, only 396 women returned to the clinic with their infants for the 6-week follow-up visit; of these mothers, 258 (59%) joined support groups and 234 (53%) opted for contraception. By the end of the study period, 209 (53%) of mother-infant pairs (n = 396) came to the clinic for at least 3 follow-up visits. CONCLUSION: Despite considerable challenges and limited resources, it was feasible to implement a PMTCT program using peer counselors in urban clinics in Zimbabwe.