['This prospective study investigated the relationship between male antenatal clinic (ANC) involvement and infant HIV-free survival.', 'From 2009 to 2013, HIV-infected pregnant women were enrolled from 6 ANCs in Nairobi, Kenya and followed with their infants until 6 weeks postpartum. Male partners were encouraged to attend antenatally through invitation letters. Men who failed to attend had questionnaires sent for self-completion postnatally. Multivariate regression was used to identify correlates of male attendance. The role of male involvement in infant outcomes of HIV infection, mortality, and HIV-free survival was examined.', 'Among 830 enrolled women, 519 (62.5%) consented to male participation and 136 (26.2%) men attended the ANC. For the 383 (73.8%) women whose partners failed to attend, 63 (16.4%) were surveyed through outreach. In multivariate analysis, male report of previous HIV testing was associated with maternal ANC attendance (adjusted odds ratio = 3.7; 95% CI: 1.5 to 8.9, P = 0.003). Thirty-five (6.6%) of 501 infants acquired HIV or died by 6 weeks of life. HIV-free survival was significantly greater among infants born to women with partner attendance (97.7%) than those without (91.3%) (P = 0.01). Infants lacking male ANC engagement had an approximately 4-fold higher risk of death or infection compared with those born to women with partner attendance (HR = 3.95, 95% CI: 1.21 to 12.89, P = 0.023). Adjusting for antiretroviral use, the risk of death or infection remained significantly greater for infants born to mothers without male participation (adjusted hazards ratio = 3.79, 95% CI: 1.15 to 12.42, P = 0.028).'] Is male Partner Participation in Antenatal Clinic Services Associated With Improved HIV-Free Survival Among Infants in Nairobi , Kenya : A Prospective Cohort Study?