A longitudinal study of HIV-infected and -uninfected pregnant women is underway in Kampala Uganda. Pregnancy and peripartum information was obtained on 1,254 women in the study delivering at Mulago Hospital between January, 1989, and February, 1991. Complications during pregnancy occurred more often to human immunodeficiency virus (HIV) seropositive women (51.8%) than HIV seronegative women (35.2%, p < 0.001). These complications included fever, urinary tract infection, and herpes zoster infections. There was a trend toward a higher maternal mortality in seropositive women (51 557) than in the seronegative women (1/697), however, this did not reach statistical significance (p = 0. 1 17). Death of the fetus or newborn was significantly more likely to occur in the seropositive group (5.6%) than the seronegative group (3.0%, p = 0.024). Furthermore, birth weights were slightly, but significantly, lower in infants born to the seropositive women (2907 g vs. 3064 g, p < 0.001). There were more infants born to seropositive women before 37 weeks gestation (12.3% vs. 8.4%, p = 0.027), and with Apgar scores <8 (11.6% vs. 7.7%, p = 0.022). HIV infection in Ugandan women is significantly associated with increased morbidity and mortality during pregnancy and adversely affects infant outcome.