To compare AIDS-defining conditions in women and men, US adult AIDS cases diagnosed between January 1988 and June 1991 and reported to the Centers for Disease Control and Prevention through June 1992 were examined. For most AIDS-defining conditions, the prevalence was similar for women and men when differences in race/ethnicity and mode of transmission were accounted for. Pneumocystis carinii pneumonia was the most prevalent condition (>50%) regardless of gender, race/ethnicity, or mode of transmission. By logistic regression analysis, among injection drug users, conditions reported significantly more frequently in women than in men include esophageal candidiasis (odds ratio [OR], 1.51; 95% confidence interval [CI], 1.40-1.62), herpes simplex virus (HSV) disease (OR, 1.68; CI, 1.46-1.94), and cytomegalovirus (CMV) disease (OR, 1.43; CI, 1.18-1.73). More knowledge of the interrelationships in women between HIV infection and secondary opportunistic infections, including candidiasis and sexually transmitted diseases (e.g., HSV and CMV) is needed.