Previous research has pointed to the efficacy of physical activity in individuals suffering from type 2 diabetes mellitus (type 2 DM). However, as with other populations, adherence to exercise programs is often problematic. This study assessed the effectiveness of a combination of exercise and psychological interventions in type 2 diabetics in terms of disease management and exercise adherence. Forty newly diagnosed type 2 diabetic subjects (54 +/- 6.5 years) took part in the study. Subjects were allocated to an exercise-only intervention (EO) or a combined exercise and psychological adherence intervention (EP) group. Adherence to the program was also monitored at a 6-month follow-up. The results confirmed a significant improvement in physiological parameters (total mass, fat mass, grip strength, peak flow, flexibility, and VO2 max) after the 12-week program in both groups (P < 0.001). The EP group had significant changes in body fat, grip strength, and peak flow (P < 0.05) in comparison to the EO group. Components of the visual analog mood scale (VAMS) were positively influenced in both groups from the therapy program (P < 0.001). The directed psychological intervention had a significant influence on attendance to the 12-week program (P < 0.001). This also resulted in significantly better adherence 6 months later (P < 0.05). In conclusion, the results have demonstrated that psychological intervention is of paramount importance for ensuring high adherence rates during exercise therapy for type 2 diabetic subjects.