Objectives: Since problem solving group training is a comprehensive, active program and based-on cognitive behavioral approach, the aim of present study was to determine the effectiveness of problem solving therapy on depression and coping style in patients with type 2 diabetes mellitus.

Methods: In an experimental design the study was done with pretest-posttest with control group. Totally 30 female clients who had inclusion criteria with score of 20-28 in Beck Depression Inventory was selected from Prophet Mohammad hospital in Tehran and divided to two groups. Then coping skills questionnaire was completed by experimental and control group. The experimental group participated in seven sessions on problem solving therapy, while the control group received no intervention. T-test analysis and variance analysis with repeated measures on one variable were used for data analysis.

Results: The results of variance analysis show that teaching problem solving therapy on Zurilla and Goldfried model lead to significant reducing emotion focused coping skills and significant increasing problem focused coping skills among patients with type 2 diabetes on the experimental group. The results also indicated significant reducing depression between this individual in experimental groups.

Discussion: The results of this study indicated that problem solving therapy could be effective way for improvement coping skill and reducing depression in patients with type 2 diabetes mellitus.