Purpose: The Acceptance Commitment Therapy(ACT) is a new treatment approach that focuses mindfulness, and it is classified as the third wave in the cognitive behavior therapy. Methods: The present study evaluated a 8-week's ACT program designed specifically for four female archers who had stress and chronic pain. In order to explore process of the ACT, the researcher utilized the qualitative case study methodology. Results: The results exhibited various experiences of participants within six components of ACT program: acceptance, defusion, self as context, focus on present, value, and commitment. Each participant described cognitive-behavioral changes through the ACT program. Conclusions: Overall, the participants reported their changes in terms of‘increasing in awareness', 'diminishing in pain and stress diminishing pain and stress', 'recognizing peer relationship', 'valued goal-setting', 'decreasing negative thought'. Finally, these results were discussed with theoretical and practical frameworks in mindfulness, and the suggestions were provided.