['The current study evaluated the efficacy of a 10-week, group-based, cognitive-behavioral stress management (CBSM) intervention relative to a half-day seminar in improving quality of life (QoL) among men who were treated for localized prostate carcinoma (PC) with either radical prostatectomy (RP) or radiation therapy.', 'Ninety-two men were assigned randomly to either the 10-week CBSM group intervention or a 1-day seminar (control group). The intervention was designed to improve QoL by helping participants to identify and effectively manage stressful experiences and was focused on the treatment-related sequelae of PC.', 'A hierarchical regression model was used to predict postintervention QoL. The final model, including all predictors and relevant covariates (i.e., income, baseline QoL, ethnicity, and group condition), explained 62.1% of the variance in QoL scores. Group assignment was a significant predictor (beta = - 0.14; P = 0.03) of QoL after the 10-week intervention period, even after controlling for ethnicity, income, and baseline QoL. Post-hoc analyses revealed that individuals in the CBSM intervention condition showed significant improvements in QoL relative to men in the 1-day control seminar. Improved QoL was mediated by greater perceived stress-management skill.'] Does cognitive-behavioral stress management improve stress-management skills and quality of life in men recovering from treatment of prostate carcinoma?