The Bureau of Labor Statistics (BLS) program of occupational injury and illness statistics is reviewed. BLS has conducted an annual survey of worker injury and illness experiences since 1971. The annual survey provides estimates of the number and incidence rate of occupational injuries and illnesses by industry and state, using uniform, stable procedures. Efforts to collect data from workmen's compensation records began in 1973. Factors associated with work related illness and types of accident or exposure were coded from the American National Standards Institute method of recording work injuries. In 1975, states were asked to label the data according to the Supplementary Data System (SDS) because it augmented data compiled from the BLS annual survey of occupational injury or illness. Lack of comparability had been the major obstacle in utilizing state data to produce national statistics. All jurisdictions except Louisiana require that a first report be filed. Information contained in the report typically comes from the employer, although insurance carriers frequently submit reports. There are four types of common information. The first identifies the employer and permits classification of the case by industry and geographic location. The second lists the employee's age, sex, salary, and occupation. A third provides an analysis of injury or illness. The fourth identifies the worker's insurance carrier, expectation of disability, and other information for processing benefit payments. Optional data is selected on the basis of potential usefulness in identifying causal relationships and generating cost estimates of occupational illness. A standard set of tabulations is generated for each state participating in the SDS. Frequently occurring injuries and illness to specified body parts are correlated by industry, occupation, accident type, and source of injury or illness. The authors conclude that SDS statistics are not substitutes for detailed case studies or annual surveys.