Postal survey research was conducted between September and November, 1986, to gather information concerning the evolution, existence and extent of mental health services available to police personnel. Questionnaires were mailed to all 366 municipal, county, and state police agencies in the United States that employed 200 or more workers. Usable data were obtained from 76.8% of the agencies surveyed. Of the 281 respondents who returned usable data, 65.1% reported the existence of mental health services available to their police personnel. The majority of respondents (58.6%) perceived their mental health programs as being equally reactive and preventive in orientation. The most frequently reported existing components were outside agency counseling, stress management seminars, and testing of potential police recruits. Over half (54.8%) of the responding police agencies reported having between 10 and 19 components in their respective mental health programs. The implementation dates and evolution of twenty-five (25) components were examined, and specific components of various police agencies were also revealed. The majority of respondents (70.7%) reported their mental health programs were available to sworn and nonsworn personnel and their families. Almost all respondents (98.3%) viewed their programs as being cost effective. Also, most agencies were satisfied with the four treatment resources …