Type-2 diabetes mellitus (T2DM) patients who were on gliclazide co-administered with metformin were changed to pre-combined glibenclamide-metformin tablets in the Endocrine Clinic, Penang Hospital. We conducted a retrospective study to evaluate the differences in glycaemic control and treatment cost following the change. Eighty patients (60% females) with a mean age of 55 years old were studied. Mean glycosylated haemoglobin (HbAlc) reduction was -0.92% (p<0.01) and -0.83% (p<0.01) after three and six months respectively. Patients with baseline HbA1c > or =8% had greater reduction in mean HbA1c (-1.36%) after six months. The treatment cost per month was reduced by 45% at 3 months (p<0.01)) and 44% at 6 months (p<0.01). The change to pre-combined glibenclamide-metformin tablets resulted in significant improvement in glycaemia and reduction in treatment cost.