The present study examined the effects of a rational emotive personal-disclosure mutual-sharing (REPDMS) intervention on the rational and irrational beliefs of a group of Greek adolescent athletes that had previously participated in four rational emotive behavior therapy (REBT) educational workshops. Measurements were taken before REBT workshops (baseline), during the REBT workshop period, and after the REPDMS session (postintervention). Further, a comparison group received REBT education, but did not receive REPDMS, allowing the between-subjects comparison between participants who received REPDMS and participants who did not. Findings support the hypotheses that REPDMS has positive effects on further reducing irrational beliefs, enhancing rational beliefs, and prolonging the duration of these positive effects, over and above REBT education alone. Qualitative inspection of the REPDMS transcript also revealed participant perceptions of REBT, and served to stimulate critical author reflections on REPDMS.