OBJECTIVES: To assess the differences in the compliance of Greek patients suffering from Type 2 diabetes mellitus who receive free combination therapy of metformin and vildagliptin compared to the diabetic patients who receive fixed combination therapy of metformin/vildagliptin. METHODS: Eight hundred adult patients inadequately controlled on twice daily 850mg metformin monotherapy who were recently added vildagliptin treatment as add on to metformin (fixed dose combination or free combination) were enrolled in the study. The observation period was 6 months. Upon treatment initiation each patient received a diary, in which they had to record their treatment on a daily basis. The diary then was returned to the physician at the final visit.  Additionally, at baseline and at the last visit of the study, patients were asked to complete a questionnaire related to their compliance of their indicated treatment. Patients were defined as compliant when they hadn’t missed any drug dose, received the correct dosage of the medication and did not interrupt their treatment. RESULTS: The preliminary results the overall study sample 63% were considered to be compliant. In the between groups analysis, it was found that 56% of patients receiving free combination were compliant with their treatment compared to a substantially higher 68% of compliant patients in the fixed combination group (p<0,005). Odds Ratio was equal to 1,647, suggesting that patients receiving free combination were 1.647 times more likely not to comply with their treatment than the patients on fixed combination. A statistically significant reduction in Hb1Ac was observed in both groups between the first and last visit (p<0,001) but not any difference between two groups, which is attributed to the short follow-up period. CONCLUSIONS: Patients on fixed dose combination treatment for Type II Diabetes are more compliant than patients on free dose combinations.  Improved compliance has been shown to improve disease management, which can prevent expensive complications.