To identify cancers that occur at higher rates in acquired immunodeficiency syndrome (AIDS) patients, the cancer experience of New York State (NYS) AIDS patients aged 15-69 years who were diagnosed between 1981 and 1994 was compared with that of the NYS general population. Sex and HIV risk group-specific standardized incidence ratios (SIRs), post-AIDS relative risks, and trends of relative risks were calculated to determine cancer risk. Among non-AIDS-related cancers, elevated SIRs were found for Hodgkin's disease (male, 8.0; female, 6.4; heterosexually infected males, 31.3); cancer of the rectum, rectosigmoid, and anus (male, 3.3; female, 3.0); trachea, bronchus, and lung (male, 3.3; female, 7.5); and brain and central nervous system (male, 3.1; female, 3.4; heterosexually infected females, 23.8) cancers. Moreover, significant trends of increasing relative risks from the pre-AIDS to the post-AIDS period were found for cancers of the rectum, rectosigmoid, and anus; trachea, bronchus, and lung; skin; and connective tissues (all sites, p < 0.05) among males. For AIDS-related cancers in women, invasive cervical cancer had an overall SIR of 9.1 (95% confidence interval: 6.9, 10.8) and a post-AIDS relative risk of 6.5 (95% confidence interval: 4.1, 9.7). This population-based registry linkage analysis evaluates cancer risk in AIDS patients by sex and risk factors and adds evidence that HIV-associated immunosuppression increases the risks of specific types of cancer.