Objective: This study aimed to evaluate the effect of the provision of drug-related information and patient education booklets on the hemoglobin A1c (HbA1c) levels of patients with type 2 diabetes mellitus.Methods: This prospective study was conducted at the Kembangan Health Center, West Jakarta, Indonesia, from March to June 2017. A total of 30 patients were divided into two equal groups: In addition to routine treatment, patients in the intervention group received drug-related information and patient education booklet, while those in the control group received no additional intervention. The provision of drug information was through direct education as well as through telephone, short messages, and booklet. HbA1c level was measured as a surrogate measure of treatment adherence. HbA1c concentration was measured at baseline and 11 weeks after the intervention.Results: Mean HbA1c level in the intervention group decreased from 8.05±0.91% at week 0 to 6.92±0.47% at week 11 after intervention (p<0.05). Conclusion:In this study, provision of drug information and patient education booklets helped to improve the patient compliance.