Background: Depression is one of the most serious problems in soldiers’ health. Acceptance and commitment therapy (ACT) is one of the used treatments for depression. This study was conducted with the aim of investigating the effectiveness of group training of ACT on depression symptoms in soldiers.

Materials and methods: A randomized controlled trial was conducted on two groups with pre-test, post-test, and two months follow-up. Beck depression inventory (BDI) was administered to 419 soldiers in a military unit. The number of participants who had higher scores than cut-off point of mild depression (>14) were 124 and of them 11 were omitted due to lack of inclusion criteria. Of the remaining 113 individuals, 40 were selected and divided randomly into “test” (20 people) and “waiting list” (20 people) groups. Six intervention sessions of training of ACT was performed for each participants of test group (one individual session and five group sessions), while waiting list group received no intervention. Data was analyzed via analysis of variance with repeated measurement using SPSS software.

Results: Based on the findings of the analysis of variance, the implementation of group training of ACT caused to a significant decrease on depression scores.

Conclusion: Results of this research indicated that group training of ACT can be useful in decreasing depression symptoms in soldiers.