Health Care Workers (HCW) are continually exposed to body fluids from patients. Some of these fluids may carry pathogens potentially transmissible to HCWs if the exposure is considered to be of "high risk" (mainly percutaneous exposure). The main agents that have been transmitted by occupational exposure are hepatitis B and C viruses and human immunodeficiency virus (HIV). The risk of transmission after risky occupational exposure to these agents is about 2-40%, 3-10% and 0.2-0.3% respectively. This review presents an operational recommendation for the management of HCWs occupationally exposed to patients' body fluids. The recommendations, through a system of algorithms focus in assessing the actual risk of the accident and the body fluid involved, the possibility of the fluid harboring a transmissible pathogen, the susceptibility of the HCW to that pathogen and the post exposure measure to be taken. For hepatitis B, pre exposure immunization is highly recommended and that vaccine in addition to hyperimmune globulin for post exposure prophylaxis is advisable. For risky occupational exposures to HIV counselling is mandatory; the role of post exposure drug prophylaxis is discussed. Hepatitis C can be occupationally transmitted; no known post exposure prophylactic measures are available. Due to the low incidence of these and other transmissible pathogens in the general population the author's recommendation is that occupational exposure to body fluids from unidentifiable or unknown sources or from patients without clinical evidence of these infections be considered as low risk, and no baseline or follow up serologic studies or measures besides counselling be taken. For other causes, the serologic follow up for exposed HCWs for each of these infections is presented.