The knowledge and preventive practices toward the risk of infection with HIV, HBV and HCV were evaluated in a sample of 254 dentists and odontostomatologies in Palermo, by answering to an anonymous questionnaire sent by mail. Overall, most of the participants showed a good knowledge of the transmission pattern of blood-borne viruses as well as good practice for personal hygiene (washing of hands, routine use of gloves, etc.). However 80.8% answered to recap needles after use and more than 40% have had at least one needle injury during the last year in their occupational setting. Moreover, nearly 24% of the interviewed declared to have not made vaccination against Hepatitis B virus infection. Statistical analysis showed a significant correlation between better knowledge, safer practice and different teaching training suggesting that odontostomatology degree might be more appropriate for a better training in preventive medicine for blood borne pathogens. Data also suggest the need of continuous worker education to reduce occupational blood exposures in dentistry.