This is the first in a series of studies designed to assist directors of occupational health and safety services in defining, measuring, predicting, and integrating total health and safety costs into useful management information. This study was structured to review recent literature on health and safety costs and to categorize costs as either direct or indirect. This delineation should aid in defining total health and safety costs, delineating priority areas for interventions to reduce costs, and evaluating the effectiveness of health and safety programs. The significance of such efforts is underscored by the reported direct health care costs for the nation's work force of over $418 billion, and indirect costs, using the lower range of estimates for such costs, of over $837 billion. Reducing the total costs of over $1.256 trillion would have major impacts on corporate productivity and competitiveness, as well as on availability of health care programs for employees. Recommendations for follow-up activities to define costs and evaluate intervention programs are provided.