Background: Type 2 diabetes mellitus (T2DM) is among the most common non-communicable diseases worldwide and Malaysia. Poor glycaemic control among T2DM patients lead to serious life-long complications. Therefore, it is imperative to study the prevalence of poor glycaemic control and its risk factors to facilitate public health physicians and clinicians in developing the best strategies to optimize glycaemic control among T2DM patients. Materials and Methods: A comparative cross-sectional study between groups of good glycaemic control and poor glycaemic control was conducted among type 2 diabetes mellitus (T2DM) patients who fulfilled study criteria in Terengganu state of Malaysia. Eligible samples in the National Diabetes Registry registered from 1st January 2021 until 31st December 2021 were included into the study. Descriptive statistics, simple and multiple logistic regressions were employed for data analysis. Result: A total of 17,165 samples were recruited in the descriptive part of the study. The prevalence of patients with poor glycaemic control in Terengganu state was 65.3% (95% CI: 0.62, 0.67). In the inferential part of the study, a total 3,700 samples were randomly selected. Multivariable analysis using multiple logistic regression revealed age, duration of diabetes, body mass index, cigarette smoking, presence of retinopathy and presence of hypertension were the significant factors associated with poor glycaemic control among T2DM patients in Terengganu state with an adjusted odds ratio (AOR) of 0.95 (95%CI:0.94, 0.96); p<0.001), AOR 1.15 (95%CI:1.13, 1.17; p<0.001), AOR 1.03 (95%CI:1.01, 1.04; p<0.001), AOR 1.45 (95%CI:1.01, 2.10; p=0.047), AOR 1.32 (95%CI:1.01, 1.73; p=0.043) and AOR 1.39 (95%CI:1.16, 1.67; p<0.001) respectively. Conclusion: Strategies focusing on the identified risk factors may improve diabetes mellitus management and avert life-long diabetic complications.