SummaryBetween November 1990 and January 1991, status of human immunodeficiency virus (HIV) infection was assessed for 522 men and 484 women attending the Comprehensive Health Centre in Kingston, Jamaica, for a new sexually transmitted disease (STD) complaint. Prevalence of HIV type 1 (HIV-1) infection was 3.1% (31 of 1,006), a tenfold rise in seroprevalence in 4.5 years. Nineteen of 517 (3.7%) heterosexual men, 3 of 5 (60%) homosexual/bisexual men, and 9 of 484 (1.9%) women were infected with HIV. In heterosexual men, factors associated with HIV infection after age adjustment included present complaint of genital ulcer [odds ratio (OR) 7.3; 95% confidence interval (CI) 1.4–72], past history of genital ulcer (OR, 4.3; CI, 1.4–12), positive MHATP syphilis serology (OR, 3.4; CI, 1.1–10), sex with a prostitute in the past month (OR, 3.8; CI, 1.1–11). Three or more sex partners in the month prior to complaint (OR, 3.6; CI, 1.0–12), and bruising during sex (OR, 4.0; CI, 1.4–13). On multiple logistic regression analysis, independent associations with HIV infection were shown for bruising during sex (OR, 3.0; CI, 1.1–8.3), positive MHATP syphilis serology (OR, 3.2; CI, 1.1–9.5), and history of genital ulcer (OR, 2.9; CI, 1.0–8.0). Among women, history of “bad blood” (syphilis) (OR, 6.6; CI, 1.4–30), self-perception of high risk for acquired immune deficiency syndrome (AIDS) (OR, 8.6; CI, 0.9–108), positive gonorrhea culture (OR 12; CI 2.1–72), HTLV-1 seropositivity (OR, 5.7; CI, 0.9–29), history of stillbirth (OR, 7.6; CI, 1.3–43), and current abnormality of the cervix (OR, ∞; CI, 1.7-∞) were associated with HIV infection. Conditions giving rise to a disruption of the genital epithelium in men such as bruising (trauma) with sex and genital ulcers may facilitate HIV transmission from women to men while inflammation of the cervix (e.g., gonorrhea) may facilitate male-to-female HIV transmission.