Purpose: This study examined whether an existentially oriented group intervention reduces existential anxiety and enhances unconditional self-acceptance among men under probation. Method: A controlled quasi-experimental pretest–posttest design was used with 20 male probationers (30–50 years), allocated to an intervention (n = 10) or control group (n = 10). The intervention consisted of eight biweekly 90-min group sessions structured around existential themes of freedom, responsibility, meaning, and authenticity. Outcomes were assessed using the Existential Concerns Questionnaire and the Unconditional Self-Acceptance Questionnaire, and data were analyzed with a 2 (group) × 2 (time) mixed-design analysis of variance. Results: The intervention group showed significant reductions in existential anxiety and significant increases in unconditional self-acceptance, with medium-to-large effect sizes, while no significant changes were observed in the control group. Conclusion: Existentially oriented group work appears to support meaning-making and self-acceptance among individuals under probation, offering a theoretically grounded complement to behavior-focused rehabilitation practices.