Information was collected by means of a mail survey of a random sample of all jails, a followup telephone survey to a stratified sample of 100 of the mail survey respondents who had assessed their mental health services as very effective, and site visits to 10 jails. Results revealed that many jails have designed and implemented innovative programs and policies to provide maximum care to the group using the limited resources available. The innovative programs and policies were grouped into six core areas: (1) screening, evaluation, and classification procedures; (2) crisis intervention and short-term treatment practices; (3) discharge planning mechanisms; (4) court liaison mechanisms; (5) diversion practices; and (6) contracting procedures. Findings indicated that establishing appropriate services for jail detainees with mental illnesses requires that the jail be seen as but one agency in a continuum of county services. Tables and appended instruments and related materials