Many of the clinical activities of correctional psychologists parallel those of their colleagues in the community. Intake assessment and evaluation, crisis management and intervention, individual psychotherapy, group psycho-education, and psychotherapy are mainstays of daily clinical practice. Depending on the mission of a particular institution, specialized treatment programs are also conducted, such as those for sex offenders, chronic pain patients, seriously mentally ill persons, and pretrial forensic assessment. Psychologists and other mental health professionals, however, are confronted with a number of unique challenges within prison environments. Base rates for antisocial personality disorder commonly exceed 50 percent in forensic and correctional settings. Ethical issues that arise in the correctional environment also present mental health providers with unique challenges. Responses to these situations must consider the potentially conflicting guidelines espoused by the American Psychological Association Code of Ethics, State licensing board requirements, specialty guidelines for forensic psychologists, and rules and regulations of the institution. This article presents several vignettes to illustrate typical situations psychologists face behind bars. The complexities of the mental illness needs of offenders and inmates requires specialized training for those who work with the 2 million men and women "behind bars." 32 references