We assessed the effectiveness of a brief structured diabetes education programme based on the concept of self-efficacy on self-care and glycaemic control using single-blind study design. One hundred and sixty-four participants with poorly controlled diabetes from two settings were randomized using computer-generated list into control (n = 82) and intervention (n = 82) groups, of which 151 completed the study. Monthly interventions over 12 weeks addressed the self-care practices of diet, physical activity, medication adherence and self-monitoring of blood glucose (SMBG). These self-care practices were assessed at Weeks 0 and 12 using pre- and post-questionnaires in both groups together with glycated haemoglobin A1c (HbA1c) and diabetes knowledge. In the intention-to-treat analysis (n = 164), the intervention group improved their SMBG (P = <0.001), physical activity (P = 0.001), HbA1c (P = 0.03), diabetes knowledge (P = <0.001) and medication adherence. At Week 12, HbA1c difference adjusted for SMBG frequency, medication adherence and weight change remained significant (P = 0.03) compared with control group. For within group comparisons, diabetes knowledge (P = <0.001), HbA1c level (P = <0.001), SMBG (P = <0.001) and medication adherence (P = 0.008) improved from baseline in the intervention group. In the control group, only diabetes knowledge improved (P = <0.001). These findings can contribute to the development of self-management diabetes education in Malaysia.