Model of study: Validation study. Objective: To evaluate the psychometric performance of the Brazilian version of the Insulin Management Diabetes Self-Efficacy Scale - IMDSES. Methodology: Reliability (internal consistency - Cronbach’s α), convergent and criterion validity were assessed. Data were gathered from 127 patients with type 2 diabetes mellitus (T2DM) in use of insulin through the application of sociodemographic and clinical instruments and the Brazilian versions of the Summary of Diabetes Self-Care Activities Measures - SDSCA and the IMDSES. Results: It was observed “ceiling effect” in Insulin domain. Reliability was confirmed in all IMDSES domains and Total Score (α=0.87). The convergent construct validity was supported by significant negative moderate to weak magnitude correlations between the scores of IMDSES domains and the scores of SDSCA domains. Criterion validity was partially supported by the weak magnitude correlation between the General Managements domain and the Total Score of IMDSES and serum levels of glycated hemoglobin (r=0.22; p=0.02). Conclusion: The Brazilian version of IMDSES presented satisfactory psychometric measures and may be useful to evaluate the effectiveness of nursing interventions aimed at optimizing the selfefficacy of the T2DM patient in the management of his treatment.