The early t o mid 1970s saw an increase in court decisions favoring the rights of patients in mental institutions. These decisions have affected numerous changes t o what constitutes patients' rights. and have had a significant impact on the practice of behavior modification in institutions. The present article provides the practitioner with a comprehensive guide t o the case law affecting behavior modification procedures. The topics covered include: the right-to-treatment concept. protection from institutional peonage. the right to enjoy basic privileges. and protection from aversive treatment.Beginning in. the early 1970s, numerous law suits were initiated on behalf of residents of institutions for the mentally ill or retarded. Some were raised in response to misuses of behavior modification procedures (Martin, 1979). As a result, the decisions in these cases have impacted greatly on the definitions of patients' rights and the practice of behavior modification in institutions.