Background: Diabetes mellitus is a serious health problem. It is considered the third leading cause of deaths among chronic diseases in the Gaza Strip, Palestine. Among diabetic patients, T2DM constitute the majority (92.2%). Medication adherence is a key determinant of therapeutic success. No studies have previously investigated medication adherence among T2DM patients in Gaza. Objectives: To assess medication adherence and its association with glycemic control among T2DM patients. Setting: Al-Rimal Martyr's clinic in Gaza, Palestine. Methods: A cross-sectional study with a convenience sample of 148 T2DM patients. The study used MMAS-8, last value of the HbA1c test, MDKT and BMQ to assess medication adherence, glycemic control, DM-related knowledge and beliefs about medicines, respectively. Main outcome measures: Level of medication adherence and rate of glycemic control. Results: The mean age of the patients was 59.4 ± 8.6 years. More than half of the patients (52%) were females. The mean adherence score was 5.5 ± 1.4. Approximately 52.7% of patients were non-adherent. 83 patients (56.1%) were poor glycemic controlled. Poor glycemic control was significantly associated with non-adherence. 95 patients (64.2%) had a low level of knowledge about DM. The mean scores of BMQ scales were 17.8 ± 3.62, 12.4 ± 3.63, 12.5 ± 3.50, 12.3 ± 2.79 for specific-necessity scale, specific-concerns scale, general-harm scale, general-overuse scale, respectively. Medication non-adherence was significantly associated with unmarried status, diet noncompliance status, and education about DM and patients' negative beliefs about medicines as a whole. Conclusion: Most patients were medication non-adherents and poor glycemic controlled. Improving patients' medication adherence may improve glycemic control.