The four major penal institutions for men in Washington state were surveyed in June 1983, to assess the quality of tuberculosis screening and the proportion of residents who were reactors. A total of 4,744 medical charts of current residents were reviewed of which 4,269 (90.0 percent) had skin test results recorded. The proportion of inmates residing in the four institutions during 1983 who were reactors was 12.5 percent. To describe the demographic characteristics and health status of reactors and nonreactors more fully, a detailed data abstraction was performed for those inmates newly admitted during 1982. The proportion of this subgroup of 1,176 men entering the prison system during 1982 who were reactors was 14.2 percent. There was no evidence of tuberculosis transmission within the institutions. Three converters were recognized. However, all three conversions were identified upon reentry of inmates following periods of release. This study supports an earlier recommendation for skin testing upon entry or reentry for residents, and only upon initial hiring of employees. The Washington State Department of Corrections was advised to continue skin testing upon entry or reentry for residents and only upon initial employment of personnel.