This study was conducted to provide some epidemiological aspects of needle stick injuries among health care workers in the eastern province in Saudi Arabia. Data about 282 injuries reported from the hospitals of the Eastern Province of Saudi Arabia were collected through specially designed questionnaire retrospectively from 1995 to 1997. Results showed that 50% of injuries occurred in the first 3 years of employment. Workers in medical and surgical specialties suffered an equal degree of reported exposure. The highest percentage (46.8%) of injuries occurred during syringe related actions. Patients' wards were the major location of incidents (48.5%) followed by ICUs and dialysis units (17.7%), theatres (15.6%) and accidents and emergency departments (13.8%). There was no significant association between injuries and type of shifts. The middle hours of the shifts showed a significant association with injuries. The pattern of injuries was significantly associated with over loaded periods of medical practices. Deficiencies in implementing the standard recommendations for prevention and control of needle stick injuries were noted in the studied hospitals.