One hundred prostitutes were studied with an aim to acquire more insight on the role of sexual transmission of HBsAg and to detect carrier state among them. All subjects were interviewed and their serum samples were tested for HBsAg by reverse passive haemagglutination method (RPHA). Eleven (11%) of the prostitutes were found to be positive for HBsAg. Their mean age was 19.3 +/- 4.9 years. The mean duration in the profession was 2.5 +/- 1.6 years. Mean number of clients for each woman per 24 hours was 10.7 +/- 1.2. Most of the prostitutes (84%) were lacking knowledge about spread and contact of the disease.