This analysis investigated variability of survival time in a cohort of 553 human immunodeficiency virus type 1 (HIV-1)-infected homosexual or bisexual men with < 50 CD4+ cells/microL. Median survival after the first CD4+ cell count < 50/microL was 1.34 years; 25% survived > or = 2 years. Multivariate analysis showed longer survival with concurrent acyclovir and zidovudine use, hemoglobin > or = 12 g/dL, and full-time employment (P < .0001). Other significant covariates associated with longer survival included African-American race, no prior AIDS illness, weight loss < 4.5 kg, and zidovudine use (with or without concurrent acyclovir) after CD4+ cells fell to < 50/microL. An easily derived score identified Multicenter AIDS Cohort Study subjects likely to survive > 2 years after CD4+ cell count was < 50/microL. Survival once CD4+ cell count fell below 50/microL may be longer for persons with a good performance status and specific clinical markers. Health care providers should consider these variables in decision-making strategies and design of clinical trials.