The prevalence of human immunodeficiency virus (HIV) infection among Central Americans is increasing. The purpose of this study was to describe the epidemiology of HIV infection among local Central American immigrants in the United States. Medical records of HIV-infected Central Americans treated at Harris County Hospital District (HCHD) facilities, the major source of indigent care in Houston, Texas, were retrospectively reviewed. Between January 1, 1990 and February 28, 1995, 18,156 Central Americans were seen at HCHD facilities, of whom 56 (13 females and 43 males) were identified as HIV-infected (0.3% versus 1.3% of all locally treated patients; P < 0.001, by test of binomial proportions). Most were from Honduras (n = 25) or El Salvador (n = 23). The mean age was 28.7 years, the mean CD4+ lymphocyte count at presentation was 173 cells/mm3, and 36 (64%) had acquired immunodeficiency syndrome (AIDS) at presentation. The 13 women (23% versus 22% for all locally treated HIV patients) were disproportionately Honduran (10 of 25 Hondurans versus 3 of 31 other Central Americans; P = 0.011). The HIV risk factors included heterosexuality in 46%, homosexuality in 29%. and a history of injection drug use in 7% (versus 10%, 57%, and 34%, respectively, for all locally treated HIV patients). The 76 diagnosed opportunistic infections (OIs) included a disproportionately greater number of patients with tuberculosis (n = 14, 33% versus 6% of all locally treated AIDS patients), toxoplasmosis (n = 10, 24% versus 7%), and cryptococcal meningitis (n = 9, 21% versus 7%), and a lower number of patients with pneumocystosis (n = 12, 29% versus 43%) and candida esophagitis (n = 2, 5% versus 16%). Central American immigrants infected with HIV present with relatively advanced disease, and the most frequent OIs are diseases for which effective prophylaxis exists. Targeted HIV screening and early intervention in this group are warranted.