Diabetes Mellitus (DM) is a major public health concern which associated with increased morbidity, mortality, health care utilization and costs. Also it is the unremitting diseases that cause high rate of death around the world. Aim of study: To assess knowledge, attitudes and practices of study participants about diabetes in Mukalla City –Yemen. Setting: The study carried out in Mukalla City –Yemen. Design: survey research design. Sample: 1650 participants selected, the Subjects were selected based on a systematic random sample of houses in district. Parts of the study: Data collected by using three tools: Socioeconomic data, Tool (a): Participants s' knowledge regarding Diabetes mellitus. (b): included knowledge about attitudes of diabetic patients. Tool (c): knowledge about practices of diabetic patients. Results: Regarding age groups of the studied participants it found that the mean of participants' age were (70± 8.34). Majority of participants had poor knowledge and practices about diabetes and its management. Also, the vast majority had negative attitude toward DM. Conclusion: This study found that participants had poor knowledge, attitude and practices toward DM. Recommendations: A continuous and repeated health education guide on diabetes for diabetic patients could be designed to include all aspects of diabetes such as the diagnostic criteria, physical exercise and guideline for managing the disease