Objectives: Hepatitis B (HBV) and C viruses (HCV) are among the most frequent blood borne pathogens. According to WHO, 5% of healthcare workers (in central Europe), are exposed to at least one sharps injury contaminated with HBV per year, 1,7% - contaminated with HCV. Aims: The aims of the study were to determine prevalence of HCV and HBV infections, vaccination efficacy against hepatitis B and usefulness of alanine aminotransferase (ALT) testing in prophylactic examinations in healthcare workers (HCWs). Material and Methods: In a group of 520 healthcare workers, a survey, laboratory and serologic tests such as ALT, HBsAg, anti-HBs, anti-HBcT and anti-HCV were carried out. Results: The study revealed a low rate of workers with presence of HBsAg and anti-HCV (1,2% and 0,8% respectively). Anti-HBcT was found in 99 subjects (19%) without a significant association with experiencing an occupational percutaneous injury. Being vaccinated against HBV was declared by 90% of the subjects. There was no relationship between ALT level rise and positive HBsAg, anti-HCV and anti-HBcT tests. Conclusion: A seroprevalence of HBV and HCV markers in HCWs found in the study is low and similar to the one found in general population. Current or past hepatitis B infections were independent of needle stick injuries. Vaccination against HBV coverage, although found to be high, should improve to 100%. Occupational prophylactic medical examinations found performing ALT test (obligatory in Poland for HCWs) not helpful. It seems that determination of anti-HBcT and anti-HCV status would be essential in pre-employment medical examinations.