Millions of children in the United States work and, despite federal and state laws, face safety hazards. Previous studies have documented large numbers of injuries suffered on the job by working children. This study describes work-related injuries to children 14-17 years old in 14 Massachusetts communities (representing 5% of the state population) based on data from emergency departments and hospital admissions collected as part of a large population-based surveillance study of injuries to children and adolescents from 1979 to 1982. An estimated 1,176 work-related injuries occurred during the three-year period, accounting for 7-13% of all injury-related emergency department visits in this age group; the proportion among 17-year-olds was 14-26%. Cuts and lacerations were the most frequent type of injury, cutting/piercing was the most common cause, and cutting instruments were the most frequently identified products. Seventeen children were hospitalized for work-related injuries during the course of the study. The estimated annual rate of occupational injury rose from 3.7/1,000 children for 14- to 15-year-olds to 44.7/1000 for 17-year-olds; these rates count all resident children, regardless of their employment status, in the denominator. Rates based on actual hours worked are much higher, and strongly suggest that working minors should be considered a high-risk group for occupational injury. This study adds to the mounting evidence that work-related injuries to children are a significant public health problem and contribute significantly to the overall incidence of injuries among children 14-17 years old. The study also demonstrates the potential of emergency department data as a valuable source of information about work-related injuries to children. Active surveillance systems combining data from emergency departments, workers' compensation, and other potential sources should be established to fully document the nature and extent of the problem. Efforts to prevent these injuries will require the combined attention of employers, parents, medical providers, educators and regulators, as well as working children themselves.