Dietary patterns high in fibre and green leafy vegetables have shown an inverse association with lower risks of type 2 diabetes mellitus and improved glycaemic control. The study aimed to investigate the effects of increased vegetable intake and conventional diabetes diet on glycaemic control among type 2 diabetic patients. White-collar workers from one telecommunication company with type 2 diabetes were assigned to two treatment groups by cluster randomisation. Individuals with known type 2 diabetes and poor glycaemic control (HbA1c ≥8 g%) were eligible and a total of 84 subjects were recruited. Subjects in the intervention group (n 41) were offered to attend seminars and intensive coaching weekly to encourage them to increase raw vegetable intake. The control group (n 40) followed the conventional diet according to the guidelines of the Indonesian Society of Endocrinology. Glycated haemoglobin (HbA1c), plasma lipids, blood pressure, vegetable intake and anthropometric measurements were assessed at baseline and end line of 12 weeks intervention. A regression analysis was conducted using differences in HbA1C between baseline and 12 weeks as the dependent variable. Student's t test was conducted for the changes of biochemical indicators from baseline to end line during the period of 12 weeks intervention. Glycaemic control improved in the intervention group and mean HbA1C, fasting blood glucose and post-prandial blood glucose in the intervention group decreased significantly along with body weight, waist circumference and total cholesterol. The finding suggested that the intervention which emphasised raw vegetable intake contributed to improved glycaemic control among Indonesian adults with type 2 diabetes mellitus.