The juvenile justice system was established to create a rehabilitative approach to prevent future crimes. Adolescents within the juvenile system suffer from many physical and mental health issues during punishment and rehabilitation. They are struggling with their mistakes and the fear of being ostracized, hated, and not accepted by society. Several studies have shown an increase in anxiety levels in adolescents in juvenile prisons. This study aims to determine effective methods can be used to reduce anxiety levels in adolescents who are undergoing rehabilitation in juvenile prisons. The Research method was Pre-Experiment Design, with Three Group Pre-Posttest, by providing brain gym exercises, progressive muscle relaxation techniques, and support therapy, then measuring the level of anxiety before and after the action using the Hamilton Rating Scale for Anxiety (HARS). The subjects in this study were 150 juvenile male prisoners (15-18 years) in Palembang, Indonesia. The results showed differences in anxiety levels between the two treatment groups using brain gym exercise and progressive muscle training (p < 0.05). However, in the control group (support therapy), there was no difference in anxiety levels (p > 0.05). There are no differences between groups using brain gym exercise and progressive muscle training (p > 0.05), but the most significant decrease in anxiety level was shown by the group that got brain gym exercise, which experienced a decrease in anxiety level (-11.24). Brain gym exercise and progressive muscle training can be provided during the rehabilitation program for adolescents in juvenile prisons as one of the activities that can reduce anxiety levels.