Ethiopia is one of the countries in which sexually transmitted infections are highly prevalent. However, the data needed to present a realistic picture of the infections are lacking. This study was therefore designed to determine the seroprevalence of syphilis and HIV-1 among pregnant women at the University of Gondar Teaching Hospital. A prospective cross-sectional hospital-based study was conducted between March and June, 2005. Blood samples were collected from 480 pregnant women attending the antenatal clinic of the hospital. Sera were tested for syphilis using the Rapid Plasma Regain (RPR) and Treponema pallidum hemagglutination (TPHA) kits, and serostatus for HIV infection was checked using rapid HIV diagnostic test kits following the manufacturers' instructions. The mean (+/-SD) age of the study participants was 26.1 (+/-7.2) years. The seroprevalence of syphilis was 1%. Antibodies against HIV-1 were detected in 9.6% of the pregnant women. A higher HIV-1 prevalence (13%) was observed in the 25- to 29-year-old age group followed by the 30- to 34-year-old age group (10.2%). Only one subject (2.2%) was found to be positive for both HIV-1 and syphilis. The data indicated a relatively declined prevalence of syphilis and HIV-1 among pregnant women in an urban antenatal clinic. However, incidence and behavioral studies are required to substantiate the findings.