OBJECTIVES: Despite a heavy burden of HIV/AIDS and other blood borne infections, few studies have investigated needle stick injuries in sub-Saharan Africa. We conducted a cross-sectional study at Mulago national referral hospital in Kampala, Uganda, to assess the occurrence and risk factors of needle stick injuries among nurses and midwives. METHODS: A total of 526 nurses and midwives involved in the direct day-to-day management of patients answered a questionnaire inquiring about occurrence of needle stick injuries and about potential predictors, including work experience, work load, working habits, training, and risk behaviour. RESULTS: A 57% of the nurses and midwives had experienced at least one needle stick injury in the last year. Only 18% had not experienced any such injury in their entire career. The rate of needle stick injuries was 4.2 per person-year. Multiple logistic regression analysis showed that the most important risk factor for needle stick injuries was lack of training on such injuries (OR 5.72, 95% CI 3.41-9.62). Other important risk factors included working for more than 40 h/week (OR 1.90, 95% CI 1.20-3.31), recapping needles most of the time (OR 1.78, 95% CI 1.11-2.86), and not using gloves when handling needles (OR 1.91, 95% CI 1.10-3.32). CONCLUSIONS: The study showed a high rate of needle stick injuries among nurses and midwives working in Uganda. The strongest predictor for needle stick injuries was lack of training. Other important risk factors were related to long working hours, working habits, and experience.