This article (Part II) and the preceding article (Part I) report the development of two clinical staging systems for HIV-infected individuals. The objective of the research reported here (Part II) was to construct a clinical staging system to predict survival in patients with AIDS. We analyzed data from VA Cooperative Study Number 298, a multicenter, double-blind, randomized trial that compared immediate versus deferred zidovudine therapy in HIV-infected individuals. Baseline variables obtained at the onset of AIDS in 204 individuals were tested in univariate Cox regression for their relationship to survival, and those that appeared predictive were examined in multivariable analysis. Based on these analyses, we constructed a new AIDS Clinical Staging System. The system is based on age, CD4+ cell count, type of first AIDS-defining condition, and functional status. The stages of the system were significant predictors of survival (p = 0.0001, log-rank test). In conclusion, valid, simple clinical staging systems for patients with AIDS can be developed based on a few variables that are readily available in clinical settings.