OBJECTIVE: To characterize the temporal changes in mortality and life expectancy among HIV-positive individuals initiating antiretroviral therapy in British Columbia, Canada, from 1993 to 2004. METHODS: This analysis was restricted to 2238 antiretroviral-naive HIV-positive individuals who started antiretroviral therapy between January 1993 and September 2004. The primary analysis endpoint was all-cause mortality stratified by four time periods: 1993-1995, 1996-1998, 1999-2001, and 2002-2004. Cox proportional hazard models, with associated 95% confidence intervals (CI), were used to estimate the hazard of death. Abridged life tables were constructed to compare life expectancies at the age of 20 years. RESULTS: Product limit estimates of the cumulative mortality rate at 12 months after therapy initiation decreased from 15.8% (+/- 1.6%) in 1993-1995 to 6.1% (+/- 1.1%) in 2002-2004. Life expectancy at the age of 20 years has increased from 9.1 years (+/- 2.3 years) in 1993-1995 to 23.6 years (+/- 4.4 years) in 2002-2004. Subjects in 1993-1995 were more likely to die than those who started therapy in 2002-2004 (hazard ratio 2.78; 95% CI 1.92-3.85). Patients who initiated dual therapy or therapies containing three or more antiretroviral drugs were, respectively, 1.49 (95% CI 1.23-1.82) and 2.56 (95% CI 2.13-3.13) times less likely to die than those who started on monotherapy. CONCLUSION: A significant and progressive decrease in mortality and increase in life expectancy were observed over the 12-year study period. The increase in life expectancy and decrease in mortality were directly associated with the use of modern forms of HAART.