CDC's National Institute for Occupational Safety and Health (NIOSH) collects data on nonfatal occupational injuries and illnesses through the National Electronic Injury Surveillance System (NEISS), an emergency department (ED)-based surveillance system. This report summarizes data for 2003. The overall number and rate of occupational injuries and illnesses did not change substantially during the 5-year period since data were last reported in 1998. In 2003, age-, sex-, and diagnosis-related patterns of injury and illness among workers treated in EDs (ED-treated injuries/illnesses) were similar to those reported in 1998. To achieve substantial decreases in these injuries and illnesses, prevention efforts must focus on effective, targeted workplace-safety interventions for diverse occupations. The Consumer Product Safety Commission (CPSC) administers NEISS, a national stratified probability sample of U.S. hospitals with 24-hour EDs that tracks product-related injuries/illnesses that are not work related. In addition, CPSC collaborates with CDC to collect data for two adjunct programs: the NIOSH work-related injuries/illnesses program (NEISS-Work) and the NEISS All-Injury Program (NEISS-AIP). NEISS-Work tracks nonfatal work-related injuries and illnesses by using the CPSC ED surveillance system. These cases are in addition to the CPSC product-related cases, and the cases are mutually exclusive. NEISS-AIP collects data on all injuries, regardless of consumer-product involvement or work relatedness (i.e., it tracks all other types of injuries in addition). The case-capture criteria are similar but not identical for the two adjunct programs (e.g., NEISS-Work includes illnesses whereas NEISS-AIP does not). This report presents data solely from NEISS-Work, which tracks cases reported at 67 of the 101 hospitals in the CPSC NEISS sample.