OBJECTIVE: To examine mortality differentials in HIV-infected and uninfected adults by demographic characteristics and the effect of non-testing on the level and pattern of age-sex specific mortality. METHODS: Three annual prospective population-based HIV surveys between 2003 and 2006 provide information regarding individual adult HIV status; households were visited twice a year to collect information about births, deaths, migrations and other demographic, health and socioeconomic data. Deaths and person-years of exposure were aggregated for each calendar year between 2004 and 2006, from which mortality rates were derived. The association between risk factors and mortality was assessed using a Cox proportional hazards model. RESULTS: The observed rate of mortality in individuals who did not consent to HIV testing was four to seven times higher, and that in HIV-infected adults 11-19 times higher than mortality in HIV-negative individuals. After adjusting for age, sex and socioeconomic status, HIV-infected individuals had a ninefold greater hazard of dying than uninfected individuals. Mortality rates increased with age and peak in the 45-54 years age group, irrespective of HIV status. Multivariably, age and sex were significantly associated with the hazard of dying, but place of residency and socioeconomic status were not. Overall mortality declined from 71 to 48 deaths per 1000 person-years between 2005 and 2006. CONCLUSION: The substantial decline in mortality after 2004 is likely to be largely attributable to the increasing availability of antiretroviral therapy. Detailed investigation of the characteristics of the not-tested individuals is needed to understand their impact on mortality patterns.