Health hazards associated with the coal liquefaction process are reviewed. Technological and operational processes are described along with hazards related to each operation. Work force estimates are provided. Findings of epidemiological surveys among coal liquefaction workers and of laboratory animal tests of the toxicity of coal liquefaction products are summarized. Recommendations are included for exposure reduction through workplace design, engineering controls, system operations, work practices, protective equipment and clothing, medical surveillance, environmental monitoring, and emergency planning and procedures. Additional research needs are also considered, such as toxicity and mutagenicity testing of liquefaction products, protective materials testing, and epidemiologic surveys.