This study aimed to describe the prevalence and predictors for male partner participation in HIV voluntary counselling and testing (VCT) at two primary healthcare clinics in Moshi urban, Tanzania as well as the effect of partner participation on uptake of HIV perinatal interventions. Pregnant women (n = 2654) in their third trimester, participating in a prevention of mother to child tranmission (PMTCT) program between June 2002 and March 2004 were encouraged to inform and invite their partners for HIV-VCT. Trained nurses conducted pre-test counselling, interviews, clinical examinations and blood sampling from the participating women and their partners. Test results were presented and post-test counselling was conducted individually or in couples, depending on the wishes of the participants. Three-hundred-and-thirty-two male partners (12.5%) came for HIV-VCT. A high proportion (131; 40%) came after the woman had delivered. HIV-seropositive women whose partners attended were three times more likely to use Nevirapine prophylaxis, four times more likely to avoid breastfeeding and six times more likely to adhere to the infant feeding method selected than those whose partners didn't attend. Women were more likely to bring their partner for VCT if they collected their own test results, were living with their partner, had a high monthly income and had expressed at enrolment the intention to share HIV results with their partner. Although PMTCT programs are presumably a good entry point for male involvement in prevention of sexual and perinatal HIV transmission, this traditional clinic-based approach reaches few men. Given the positive influence male participation has on the acceptance of perinatal interventions, a different approach for promoting male participation in VCT is urgently required. Within PMTCT programs, counseling should emphasize the advantages of partner participation to encourage women to inform and convince male partners to come for VCT. Also, promotion of couple VCT outside antenatal settings in male friendly and accessible settings should be given priority.