The results of postmortem investigation of 101 cases of HIV infection at its different stages in Saint-Petersburg are analyzed. The challenges to a pathologist performing the autopsy are discussed. There has been an increase in the number of deaths since 2000, among drug users in particular. Macrophacytic transformation and specific HIV-related encephalitis are among the most important changes directly associated with immunodeficiency virus. Among secondary infections, cryptococcosis, cytomegaly, pneumocystosis, and tuberculosis are most common and significant.