Background and aims: Self-care behavior is associated with the risk of microvascular and macrovascular complications. Self-care behaviors can be improved through positive thinking, attitude, and knowledge. Cognitive behavioral therapy (CBT) can be one of the interventions for improving self-care behaviors. However, the ideal model and duration of the intervention and an effective assessment instrument to measure the improvement in self-care behaviors remain unidentified. Therefore, this review aimed to assess the effectiveness of CBT, including its models, duration, and instruments, in improving self-care behaviors in patients with type 2 diabetes mellitus (T2DM). Methods: The Scopus, Cochrane Library, PubMed, EBSCO Host, Directory of Open Access Journals, GARUDA, Taylor & Francis, and Gray Literature databases were systematically searched to identify studies that were in English and published in 2011-2021. The quality of the identified articles was assessed using The Critical Appraisal Skill Programme. Results: We found 368 patients in seven randomized controlled trials. CBT was significantly effective in improving overall self-care behavior, including blood glucose monitoring, physical activity, and medication compliance. Conclusion: Individual and group CBT interventions applied face-to-face, via telephone, and via internet show an increase in self-care behavior in patients with T2DM. The duration of treatment had a significant effect at 3 months to 1 year with 12-21 sessions. CBT is performed by a CBT licensed nurse or psychiatrist, nutritionist, CBT psychologist with experience in diabetes care, doctors, research students. (C) 2022 Diabetes India. Published by Elsevier Ltd. All rights reserved.