We compared the survival of patients following the first AIDS event in Croatia from the period 1986-1996 to the period 1997-2000. A total of 72 (81.8%) out of 88 patients from 1986-1996 and 18 (32.1%) out of 56 from 1997-2000 died. Survival following the first AIDS-defining illness markedly improved in the period 1997-2000 compared to the period 1986-1996 (adjusted Hazard Ratio (HR) for patients surviving more than 6 months: 0.11, 95% confidence interval (95% CI) = 0.04-0.29). A CD4+ cell count of < 100 x 10(6)/L was an independent risk factor for patients surviving up to 2 years (adjusted HR = 1.96, 95% CI = 1.1-3.43, p = 0.02). Patients with tuberculosis or fungal infections had a longer survival when compared to other diagnosis (adjusted HR = 0.53, 95% CI = 0.32-0.90, p = 0.01). However, despite dramatic survival benefit of combination antiretroviral therapy, mortality at six months following the first AIDS event was similar in the two study periods and the one-year probability of death was still substantial (27.2%) in the period 1997-2000.