Objectives: Compliance to treatment is important for the management of type 2 diabetes mellitus (DM) and the prevention of complications.The purpose of the study was to develop a scale and test its psychometric properties for the treatment compliance of the diabetic Turkish population.Methods: This multicenter study was conducted in four training and research hospitals.The convenience sample consisted of 350 patients with type 2 DM.The items of the scale were determined after a literature review and qualitative interviews with the patients.Items were psychometrically analyzed.Content validity of the scale was evaluated using opinions from experts and a pilot study.Principal component analysis and the varimax rotation technique were used to evaluate construct validity in exploratory factor analysis.Criterion validity was evaluated with the Attitudes Towards Diabetes Scale,a subgroup of the Diabetes Care Profile scale.Reliability was evaluated with Cronbach’s α coefficient and test-retest analysis of intal consistency.Results: The scale consisted of 7 factors that explained 47.36％ of the total variance.The KMO test was conducted to determine whether the sample size was sufficient before the factor analysis.The KMO test result of the data was 0.75.The Cronbach’s α value of the sample was 0.77.The test-retest reliability analysis result was r =0.991.We found a positive correlation between total scores of the developed scale and the Attitudes Towards Diabetes Scale (r =0.31).Conclusion: The results of the study demonstrated that the scale with 30 items is a valid and reliable scale for the evaluation of patient compliance with type 2 DM treatment.Thus,by using this scale,nurses and healthcare providers can evaluate the treatment compliance of patients with type 2 DM.