Introduction: Illness Perception and self-care behaviors are essential elements in treatment and management of patients with diabetes. The aim of this study was to investigate the effect of group counseling with a cognitive-behavioral approach to illness perceived and self-care behaviors in middle-aged women with type 2 diabetes (T2D). Methods: The present study is a quasi-experimental study with two groups of intervention and control in parallel with pre-test, post-test and one-month control in Isfahan, Iran, comprehensive health centers. For each group, 32 middle-aged women with T2D were selected by convenience sampling. Both groups received routine care of diabetic patients, but the experimental group received a cognitive behavioral group-counseling program. Data was collected through demographic questionnaire, the illness perception questionnair (IPQ), and summary of diabetes self-care activity (SDCS) and a checklist. Data was analyzed by SPSS 16 software using descriptive statistics, Chi-square test and independent t-test with P-values are less than 0. 05. Results: The groups were not significantly different demographically. The mean age was 38. 65± 4. 23 and 39. 19± 4. 87, and the duration of diagnosis was 2 years and less. Of patients, 77% had a history of hypertension or hyperlipidemia or both in both groups. There were no significant differences in self-care behaviors (t=-0. 0222, P=0. 859) and illness perception (t=-0. 178, P=0. 859) in the pre-test. However, in the post-test, the intervention group showed a significant improvement in self-care behaviors (t=4. 25, P=0. 01) and disease perception (t=3. 93, standard deviation=0. 87). There was also an improvement in self-care behaviors (t=4. 41 and P=0. 014) and illness perception (t=414 and P=0. 01) in the follow-up period, indicating the persistence of changes in counseling Conclusion: Group counseling based on cognitive-behavioral approach can enhance the perception of disease and self-care behaviors in T2D. Therefore, it can be used as a therapeutic approach to medication for patients with T2DM.