ObjectiveHome-based couples HIV testing and counseling and HIV self-testing (HIVST) for pregnant women can promote HIV status disclosure and male partner testing; however, cost data are lacking. We examined a home-based couples intervention (HBCI) and HIVST intervention costs per couple (unit cost) during pregnancy and postpartum in Kenya. MethodsThis randomized controlled trial is comparing HBCI and HIVST for couples among pregnant women attending antenatal care clinics in two counties in southwestern Kenya. We used micro-costing to estimate the unit cost per couple receiving the intervention as the total of direct and indirect costs for each study arm in 2019 US$. We used a one-month window to conduct a time and motion study to determine personnel effort and resources. We then compared the unit cost by arm, identified key cost drivers, and conducted sensitivity analyses for cost uncertainties. ResultsAt base-case, the unit cost was $129.01 and $41.99, respectively, for HBCI and HIVST. Personnel comprised half of the unit cost for both arms. Staff spent more time on activities related to participant engagement in HBCI (accounting for 6.4% of the unit cost) than in HIVST (2.3%). Staff training was another key cost driver in HBCI (20.1% of the unit cost compared to 12.5% in HIVST). Sensitivity analyses revealed that the unit cost ranges were $104.64-$154.54 for HBCI and $30.49-$56.59 for HIVST. ConclusionsOur findings may guide spending decisions for future HIV prevention and treatment programs for pregnant couples in resource-limited settings such as Kenya.