Abstract: Background: Diabetes Mellitus is a global health problem that requires continuous medical care, self-monitoring, and management. Self-care is a cornerstone in the management of diabetes and the prevention of complications. Suboptimal management of diabetes mellitus can lead to serious complications that impose a huge burden on individuals and healthcare systems. Aim: This study aimed to assess the self-care activities among patients with type-2 diabetes mellitus in Bahrain. Methodology: A cross-sectional study was conducted among adult patients with type-2 diabetes mellitus attending diabetic clinics in the primary health care centers in Bahrain. A convenient sampling technique was used to recruit the participants. The data collection tool consisted of 3 parts; sociodemographic data, clinical data, and the diabetes self-care activities questionnaire. Summary of Diabetes Self-care Activities Scale was used to assess self-care activities. Results: The data were analyzed using Statistical Package for Social Sciences software version 26.0. Mann Whitney test and Kruskal Wallis test were used to determine the significant difference in the means. A total of 210 patients with type-2 diabetes mellitus were included in the study. Almost half of the respondents were males (51.4%), (76.7%) were Bahraini, around 40% of them belonged to the 51-60 years age group (39.5%) and (81.9%) were married. Of all participants, (16.7%) were smokers. The most practiced self- care activities were adopting specific diet regimens with a percent of adherence of 57.1% and foot care at 51.4%, while physical activities and blood sugar testing were the least performed activities 41.4% and 27.1% respectively. Males and Bahraini patients reported higher levels of exercise compared to females and non-Bahraini patients, respectively (P<0.001 and P=0.010, respectively). Married patients followed eating plan and were more physically active compared to other groups (P=0.030 and P=0.017, respectively). In general, patients with a long history of diabetes mellitus and patients who were on insulin were significantly more likely to check their blood glucose and do foot care practices. Conclusion: In conclusion, the study showed suboptimal levels of self-care among patients with type-2 diabetes mellitus. The least practiced self-care measures were monitoring plasma glucose levels and doing physical activities while the most practiced measures were adherence to specific diet advice and foot care practices. Urgent interventions to improve patients' awareness and compliance with diabetes self-care activities are needed. Keywords: Type 2 diabetes; Self-care activities; Patients; Nurses.