Needle stick injury, in which blood-borne pathogens including Human Immune-Deficiency virus and hepatitis B virus are transmitted, is one of the major occupational hazards that health professionals face everyday. In order to provide basic data for the development of educational programs for health professionals aimed at preventing and effectively managing needle stick injuries, a retrospective descriptive study was carried out .The subjects of the study were 630 health professionals, 499 nurses and 131 physicians, from two university hospitals in Seoul, Korea. Data on episodes of needle stick experiences over the past is months September 1994 through August 1995, were collected between September 1 and 7, 1995. A Questionaire developed by the researcher was used. The frequencies and the percentile score for episodes of needle stick injuries were calculated using the PC-SAS program. The differences and similarities in reference to the structure, career, and specialty variables were analysed by X$^2$-tests. Results are as follows : 1. Of the sample, 521(82.7%) reported a needle stick injury, 33.4% reported 3 or more episodes of needle stick injuries. 2. The needle stick injuries occured in the following processes : process of percutaneous venepuncture for intra-venous injection and infusion(55.3%), medical examination and treatment(48.9%), per-cutaneous venepuncture for blood sampling (46.3%) and intra-muscular injection(42.2%). 3. The study showed that needle stick injuries occured before(19%), during(25%), and after (56%) client treatment. The major causes of needle stick injuries were perceived to be hastiness(82.2%) and carelessness(48.3%). Of these injuries, 91.8% occured in emergency situations. 4. Follow of care for the injury consisted of : treating the injured site immediately using disinfectants(89.7%), reviewing the clinical records of the patient involved(84.2%), immunological investigation for the status of antibodies(11.1%) and self-medication of antibiotics (10.7%). Only 16.3% of the total episodes were founded to have been reported to the administrative unit. 5. The length of clinical experience of the nurses, clinical specialty and length of clinical experience in physicians were found to have influenced the episodes of needle stick injuries ; nurses with less than 1 year and with more than 6 years of clinical experiences had significantly lower levels (X$^2$=25.04, P=.00), surgeons had significantly higher levels (X$^2$=9.89, P=.02) compared to that of internists and interns, higher(X$^2$=4.54, P=.03)than residents.