Study objective. To record descriptions of occupational exposures to blood, determine factors predictive of exposure, and identify interventions that might reduce the frequency of exposure. design. An analytic, cross-sectional survey. study population. A total of 601 nurses from surgical wards, operating rooms, and emergency departments. study instrument. An anonymous questionnaire developed by the authors on the basis of previously published guidelines was distributed between January and March 2003. sampling. Random, with 18 hospitals selected from 2 urban and rural locations. results. Almost half of respondents reported having had at least 1 puncture injury during the preceding year, 1 in 5 had exposure via mucous membranes, and more than half had worked at least once with a recent abrasion or cut on their hands. The number of injuries was independent of age (), duration of practice (), and workplace setting (). The percentage of nurses without Pp. 26 Pp. 21 Pp. 78 percutaneous exposure during the preceding year was significantly higher in the group that received special HIV/AIDS training than in the group that did not (95% confidence interval, 5.8-24.1%;). The most recent exposure was primarily caused by hollow-bore P < .002 needles, involved the palm and fingers II-V, was self-inflicted, took place during an elective procedure, and was not reported to the hospital's infection control center by 74% of respondents. The most common reason for not reporting the exposure (38% of cases) was the conviction that the source patient was not infected. conclusions. Because of the large number of occupational exposures to blood, especially those due to injuries with hollow-bore needles, nurses should adopt more adequate behavioral strategies to prevent the transmission of blood-borne pathogens. Policies for providing adequate education programs tailored to encourage nurses to report all exposures are urgently required.