Objectives:Diabetes mellitus is a metabolic disorder of major public health importance due to its prevalence and potential health complication. The success of long-term maintenance therapy of diabetes patients depends largely on their ability to adherence to self-care practices. Africa’s most populous country, Ethiopia, has the highest burden of diabetes mellitus. However, studies on self-care activities of diabetic patients are limited. Therefore, this study measures the level of self-care activities of diabetic patients in a follow-up clinic of public hospitals in Harar and Dire Dawa, Eastern Ethiopia.Methods:A hospital-based cross-sectional study was conducted on 320 randomly selected diabetic patients in Harar and Dire Dawa. A standard diabetic self-care activity interview tool was used to collect the data. Data were entered into Epi-data v 3.1 and STATA v 14.2 was used for analysis. Our outcome variable, self-care activities, has three ordered categories and a robust Ordinal logistic regression was used to identify predictors. All statistical tests with p-value <0.05 were considered as statistically significant.Results:The self-care activities of study participants were rated good for 38.1% (95% confidence interval: 32.94, 43.60). Being rural residents (adjusted odds ratio = 0.38, 95% confidence interval: 0.17, 0.82), attended secondary education (adjusted odds ratio = 2.96, 95% confidence interval: 1.51, 5.78), uncontrolled blood glucose (adjusted odds ratio = 1.68, 95% confidence interval: 1.02, 2.79), and had diabetic complications (one, adjusted odds ratio = 1.91, 95% confidence interval: 1.08, 3.38; two or more, adjusted odds ratio = 4.71, 95% confidence interval: 1.81, 12.25) were significantly associated with the better diabetes mellitus self-care activities.Conclusion:Significant number of diabetes mellitus patients living in rural areas did not adhere to diabetic self-care activities. This is more evident among participants who have limited or no formal education and patients with controlled blood glucose level. Therefore, individualized diabetic lifestyle education programs in follow-up clinics should target these population groups to improve self-care.