An anonymous unlinked seroprevalence study of HIV, HBV and HCV infections has been conducted on 485 sera consecutively submitted to the virology laboratory to be tested for HBsAg; sera came from patients attending general surgery at San Camillo Hospital in Rome. Carriers of HBsAg were 12 (2.5%); antibodies against HIV have been identified in 4 sera (0.8%) and against HCV in 35 (7.2) by ELISA (first generation assay); 25/35 of anti HCV ELISA positive sera were reactive also by RIBA (first generation assay). The observed prevalences of potentially infectious patients represent a risk of occupational transmission for health care workers. Vaccination against HBV, adherence with universal precautions and development of safer surgical devices and techniques are needed to prevent the risk of exposure and, consequently, of occupational acquired infections.