HIV-seroconversion during pregnancy is a serious concern throughout South Africa, where an estimated 35 to 40% of pregnant women have HIV/AIDS and drop-out is high at all stages of the prevention-of-mother-to-child-transmission (PMTCT) process. The likelihood of PMTCT success may be linked to partner support, yet male involvement in antenatal care remains low. This qualitative study examined the influence of pregnant couples' expectations, experiences and perceptions on sexual communication and male involvement in PMTCT. A total of 119 couples participated in a comprehensive intervention in 12 antenatal clinics throughout South Africa. Data were collected between December 2010 to June 2011 and analysed using a grounded theory approach. Findings point to the importance of sexual communication as a factor influencing PMTCT male involvement. Analysis of themes lends support to improving communication between couples, encouraging dialogue among men and increasing male involvement in PMTCT to bridge the gap between knowledge and sexual behaviour change.