Type 2 diabetes is a common and chronic disease that endangers people's mental health. The aim of this study was to evaluate the impact of cognitive-behavioral group therapies and positive treatment on increasing psychological hardiness and quality of life in women with type 2 diabetes. This is a quasi-experimental study with pretest-posttest, two experimental groups and a control group. The study population included the people suffering from type 2 diabetes in Tehran, Iran in 2015-2016. The statistical sample consisted of 45 people (three groups of 15 people) with type 2 diabetes who were selected using the convenience sampling method. The two intervention groups were in the intervention sessions of cognitive-behavioral group therapies and positive treatment, respectively, and the control group did not receive any intervention during this period. The required data were collected using standard questionnaires and analyzed using SPSS software 22. The results of MANCOVA test showed that cognitive-behavioral therapies and positive treatment are effective in improving the quality of life and increasing the psychological hardiness of patients (p < 0.01). The results of t-test further indicated that, in some components, the effect of cognitive-behavioral therapies is more desirable than positive treatment, and it has a greater effect on improving the quality of life and psychological hardiness in women with type 2 diabetes. It seems that cognitive-behavioral group therapies and positive treatment have desirable effects on improving the quality of life and increasing the psychological hardiness of patients. Therefore, the use of these psychological interventions in therapeutic settings is recommended.