OBJECTIVE: HIV counseling and testing (HCT) is a key intervention for HIV/AIDS control, and new strategies have been developed for expanding coverage in developing countries. We compared costs and outcomes of four HCT strategies in Uganda. DESIGN: A retrospective cohort of 84 323 individuals received HCT at one of four Ugandan HCT programs between June 2003 and September 2005. HCT strategies assessed were stand-alone HCT; hospital-based HCT; household-member HCT; and door-to-door HCT. METHODS: We collected data on client volume, demographics, prior testing and HIV diagnosis from project monitoring systems, and cost data from project accounts and personnel interviews. Strategies were compared in terms of costs and effectiveness at reaching key population groups. RESULTS: Household-member and door-to-door HCT strategies reached the largest proportion of previously untested individuals (>90% of all clients). Hospital-based HCT diagnosed the greatest proportion of HIV-infected individuals (27% prevalence), followed by stand-alone HCT (19%). Household-member HCT identified the highest percentage of discordant couples; however, this was a small fraction of total clients (<4%). Costs per client (2007 USD) were $19.26 for stand-alone HCT, $11.68 for hospital-based HCT, $13.85 for household-member HCT, and $8.29 for door-to-door-HCT. CONCLUSION: All testing strategies had relatively low per client costs. Hospital-based HCT most readily identified HIV-infected individuals eligible for treatment, whereas home-based strategies more efficiently reached populations with low rates of prior testing and HIV-infected people with higher CD4 cell counts. Multiple HCT strategies with different costs and efficiencies can be used to meet the UNAIDS/WHO call for universal HCT access by 2010.