Aim: The aim of the present study was to investigate the effectiveness of acceptance and commitment therapy on the psychological capital of bullied students. Method: The research design was quasi-experimental type with a pre-test-post-test design with a control group. The statistical population of the research includes all male students of the first secondary school in Rasht city in the academic year 2022-2023. After implementing the bullying questionnaire, 30 students were selected as the bully group and they were randomly placed in two experimental and control groups (15 people in each group). In order to collect data, the psychological capital questionnaire (Luthans, 2007) was used. The experimental group underwent acceptance and commitment therapy for 8 sessions of 90 minutes, and the control group did not receive any training. Results:The results showed that acceptance and commitment therapy led to a significant increase in psychological capital and its components (P<0.001). Conclusion: Based on this, acceptance and commitment therapy can be considered as an effective intervention in increasing the psychological capital of bullied students through the promotion of psychological flexibility.
