This paper discusses the economic and legal incentives for using biological monitoring to detect occupational disease. The limitations of workers' compensation statutes and the various theories of liability for occupational disease are described. After a description of the general principles governing liability, the following issues are discussed: the liability that may result when employers fail to biologically monitor their employees; the company physician's personal liability; liability of manufacturers of hazardous substances; and the employer's duty to report known diseases to affected employees.