The study first interviewed respondents regarding their demographic characteristics and personal histories and then administered the SCL-90 to measure psychological problems, the Jail Preference Inventory to assess environmental needs, the Self-Anchoring Striving Scale to measure environmental satisfaction, and the Environmental Quality Scale to determine jail features important to the confined. Additional interviews were conducted with persons still confined 5 days after the initial interview, a small group of prisoners who had been confined in a mental hospital, and jail staff. The jail sites represented an urban, suburban, and rural facility. A statistical profile of the respondents' characteristics emphasizes that, in comparison with the general population, the jail inmates were poor, unemployed, and undereducated. They were likely to be black and veteran of jail. Separate chapters detail the results of the various psychological test. Overall, the level of distress expressed upon initial incarceration increased rather sharply. This stress decreased after 5 days of confinement, but did not return to preconfinement levels. Jail inmates most prized assistance, support, and certainty. A subsidiary analysis of inmate subculture items showed that experience inmates enetred jail, assessed how long they would be in, and readapted readily to the inmate subculture. The report also examines the role of jails as a repository for former mental patients, presenting five mental patient/offender profile types derived from interviews. Jail staff ranked overcrowding as the most serious problem by a substantial margin, followed by lack of activities for inmates and inmates with psychological problems. The report discusses the research design, prior studies on the effects of jail confinement, and implications of the study's findings for practioners. Tables, questionnaires, and approximately 100 references are supplied.