New recommendations regarding prophylaxis of healthcare workers exposed to human immunodeficiency virus (HIV) prompted us to examine the frequency and nature of percutaneous injuries at this hospital. Four previously defined risk factors for transmission of HIV were evaluated. Between 1993 and 1995, 1,070 percutaneous injuries were reported, including 11 in which the source patient had acquired immunodeficiency syndrome (AIDS). Five of these injuries involved at least one risk factor for transmission. No source patient was found to have AIDS as a result of testing following exposure. We conclude that high-risk injuries are infrequent and that postexposure prophylaxis will not increase costs greatly at this medical center.