The purpose of this two-study project was to determine the effects of cognitive bibliotherapy for the treatment of depressive symptoms in jail and prison inmates. Participants in both samples were randomly assigned to either a treatment group that received the 4-week bibliotherapy program or a delayed-treatment control group. In the jail sample, which served as a pilot study for the more detailed prison study, the treatment group showed greater improvement on the A. T. Beck and R. A. Steer Beck Depression Inventory, 1993, Psychological Corporation, San Antonio, TX and the DAS (M. M. Weissman, & A. T. Beck Development and validation of the Dysfunctional Attitudes Scale: A preliminary investigation; paper presented at the meeting of the American Educational Research Association, November, 1978, Toronto, ON, Canada). In the prison sample, results indicated that the treatment group showed greater improvement on the HRSD (M. Hamilton, Development of a rating scale for primary depressive illness, British Journal of Social & Clinical Psychology, Vol. 6, 1967, pp. 278–296) and the A. T. Beck, R. A. Steer, & G. K. Brown Beck Depression Inventory (2nd ed.), 1996, Psychological Corporation, San Antonio, TX. Approximately half of the treated participants achieved clinically significant change. Analyses of the follow-up data revealed maintenance of treatment gains in the prison and jail samples. In the prison study, significant changes were also observed on a general measure of psychological distress. Overall, results suggest that cognitive bibliotherapy may be efficacious for depressed inmates.