Introduction: Life satisfaction and effective self-care management play an important role in keeping diabetes mellitus under control. The study aim was to determine the levels of self-care management and life satisfaction in patients with diabetes mellitus to explore their association and determine any predictive factors for self-man-agement. Methods: This cross-sectional study was conducted with 210 patients with Type 2 Diabetes Mellitus (DM) treated at a university hospital's endocrinology clinic between February 2019 and April 2019. The data were collected using a Personal Information Form, the Self-Care Management Scale in Chronic Illness and the Satisfaction with Life Scale. To analyse the data, descriptive statistics, t-tests, ANOVA, Pearson?s correlation and multivariate linear regression analysis were utilised. Results: The total score of the patients with DM in the Self-Care Management Scale was 113.34 +/- 17.12, while the subscale scores of the dimensions of self-support and social support were respectively 72.21 +/- 11.55 and 41.08 +/- 9.84. Their total score of Satisfaction with Life Scale was 18.42 +/- 9.03. The two components com-prising patients' self-care management (self-support and social support), as well as total self-care management levels (r(2) : 0.52, p < 0.01) showed correlation with life satisfaction. Conclusion: The self-care management and life satisfaction levels of the patients were average. Diabetes self-care management is significantly associated life satisfaction levels.