Abstract: Objective To study the correlation between body mass index(BMI) and diabetes in the elderly residents in Foshan. Methods A total of 3 382 people above 60 years old participated in this questionnaire-based survey, with their blood pressure, height, body weight, and blood glucose measured and oral glucose tolerance test performed. Results The prevalence rates of diabetes in the elderly subjects with obesity, overweight, normal weight, and underweight were 31.58%, 22.84%, 15.65% and 9.40%, respectively. The prevalence rate of impaired glucose tolerance(IGT) in relation to obesity, overweight, normal weight, and underweight were 67.94%, 56.14%, 46.58% and 38.35%, respectively. A higher mean BMI was accompanied by a greater prevalence of diabetes. The average BMI was 23.9±3.3 kg/m² in diabetic subjects, 23.4±3.4 kg/m² in subjects with IGT, and 22.6±3.2 kg/m² in normal elderly subjects. Conclusion There is a close correlation between BMI and diabetes.