Background: Evaluations indicate low levels of quality of life in people with HIV. Can Acceptance and Commitment Therapy improve quality of life for these patients? Aims: The aim of the present study was to investigate the effect of group therapy based on Acceptance and Commitment Therapy on enhancing quality of life in people with HIV. Method: The research method was experimental with pretest -posttest with control group and follow up design. The statistical population included 42 men with HIV in Alborz province who were volunteered to participate in this project in spring 98. Twenty patients were selected by random sampling and were divided into intervention and control groups (n=10 each). The intervention group participated in 12 weekly intervention sessions. The sessions were based on the Einberg (2016) Package. The McGill Quality of Life Questionnaire (Cohen et al, 1995) was administered in two groups. Mixed ANOVA was performed to evaluate the results. Results: The results showed that the effect of group therapy based on Acceptance and Commitment Therapy on increasing quality of life (p= 0/029) was significant. The results were also significant in the physical (p= 0/024) and psychological (p= 0/007) subscales. But in the subscales of general attitude (p= 0/12), existential (p= 0/067) and support (p= 0/055) was not significant. Conclusions: As a result, using group therapy based on Acceptance and Commitment Therapy can improve the quality of life in people with HIV.