Abstract INTRODUCTION: Central obesity is one of the coronary artery diseases (CAD) risk factors that has been regarded, recently. There are several methods for measuring abdominal obesity. We used abdominal diameter index (ADI) as an index of abdominal obesity and studied its relation to CAD. METHODS: 180 patients [90 male and 90 female] with CAD were studied in Shahid Chamran Hospital affiliated to Isfahan University of Medical Sciences. Patients were stratified as normal group (without significant occlusion of CAD) and group with coronary artery diseases (over than 75% occlusion in at least one of the coronary arteries: LMA, LAD, RCA, LCX). People with diabetes, hypertension, hyperlipidemia, foot paralysis, edema, hypertriglyceridemia and ascitis were excluded. ADI was compared between groups. The relationship between ADI and coronary artery occlusion was tested in patients with CAD. RESULTS: The mean of ADI in patients with CAD was significantly higher than normal group (0.52 ±0.85 versus 0.41 ± 0.082 in men and 0.51 ± 0.15 versus 0.42 ± 0.07 in women, respectively) (P < 0.05). Significant correlation was seen between ADI and coronary artery occlusion only in women (P < 0.05). ADI had not any significant correlation with hyperlipidemia, diabetes, high blood pressure, sex, and smoking. CONCLUSION: It seems that ADI, as an index of central obesity might be included as an independent predictor of CAD. This hypothesis needs large follow up studies to be tested in future. Keywords: Abdominal diameter, central obesity, waist to hip ratio, coronary artery disease.