Traumatic Incident Reduction (TIR) is a one session intervention that proved effective in reducing symptoms of depression, anxiety, and posttraumatic stress disorder in an experimental outcome study of a randomly assigned sample of 123 female federal prison inmates. TIR also proved effective in increasing levels of self-efficacy (expectancy of success) in these women. This article discusses in detail both the treatment protocol offered the women inmates and the research design and results of the experimental outcome study. The article also makes suggestions for practice and research related to traumatized women inmates. (PsycINFO Database Record (c) 2019 APA, all rights reserved)