The importance of male spousal involvement in the prevention of mother-to-child transmission (pMTCT) programs is incremental to maintain family health and adherence to human immunodeficiency virus (HIV) treatment and prevention regimens. This study examined reasons for men's involvement in pMTCT initiatives sought by their wives and other HIV-related services in western Kenya. Data were collected from 146 men and women during 16 focus groups across four different HIV-related clinics. Four different groups of participants were recruited: (1) male spouses of women enrolled in pMTCT within the past 12 months; (2) married men who were participating in support groups of the AMPATH Support Network; (3) married women living with HIV who were currently enrolled in pMTCT; and (4) married women who were HIV negative and currently enrolled in pMTCT. Demographic information was collected from each participant using a written questionnaire. Focus groups were conducted to determine the factors associated with men's participation in pMTCT services. From the emergent themes revealed by the focus groups, several intervention strategies were identified to increase male involvement in HIV-related services, specifically pMTCT. They include: couple's counseling, weekend clinic hours or extended weekday hours, community education regarding HIV-related services offered at clinics, and making clinics more male-oriented. These findings provide a starting point for the development of interventions to increase men's involvement in pMTCT programs.