The Effect of Ramadan fasting on certain anthropometric, clinical and biochemical parameters among type 2 diabetic subjects has been discussed in this book. Ninety two type 2 diabetic subjects (age 47±9 years, M±SD) selected from a tertiary care hospital of the Diabetic Association of Bangladesh, was studied 1-4 weeks before and 3-4 weeks of Ramadan. There was no significant difference between before Ramadan and during Ramadan values of BMI and waist-to-hip ratio. However, during Ramadan fasting serum glucose, fructosamine, total cholesterol and creatinine were significantly higher compared to before Ramadan values (p>0.0001). Before Ramadan the duration of physical exercise was adequate in 30% subjects, but during Ramadan the corresponding value decreased to only 8% . Total energy expenditure of the subjects was significantly lower during Ramadan (2178.2±215.9) compared to before Ramadan value (2232.8±209.7, p>0.0001). The data suggest that Ramadan fasting is associated with a deterioration of metabolic control in diabetic patients. Coordinated education and motivation program should be undertaken to increase energy expenditure by physical activity.