To determine the nature and processing of these lawsuits, data on closed cases were obtained from the 1968-84 annual statistics of the Administrative Office of the U.S. Courts (AO). These data indicate the general stages at which cases are terminated. Comparisons of disposition time, disposition method, and case outcome were made by examining cases closed between July 1, 1979, and June 30, 1983, in four selected U.S. district courts. Data were also obtained from individual case files for the U.S. district court for Colorado to determine grievance types, disposition patterns, the influence of writ writers, and the role of Federal magistrates. The analysis of State level factors that predict inmate litigation rates relied on AO annual reports. Secondary sources were used to obtain information on State correctional system characteristics. There was little evidence that inmates' cases received less attention than other civil cases. Although these cases burdened the courts' resources, the burden was borne primarily by Federal magistrates. Inmates' perception that litigation is the primary remedy for grievances was the most influential correlate of lawsuits. The characteristics of State correctional systems were not significant factors. Inmates' litigious attitudes can be changed by instituting effective grievance systems. State administrative remedies should be exhausted before an inmate lawsuit is permitted in a Federal court. Tabular data and 61-item bibliography.