Cardiac syndrome X is defined by an angina pectoris with normal or near normal coronary angiogram.We evaluated the association of Helicobacter pylori (HP) infection with cardiac syndrome X (CSX). We studied 30 patients with CSX, 30 cases with stable angina and also 30 healthy controls. All three groups underwent urea breath test (UBT). Fifty percent (15 out of 30) of CSX patients had positive UBT result (> or =200 dpm), while two other groups did not have the positive results. Regarding high prevalence of HP infection in patients with CSX in our study and probable causative effect of chronic infection in coronary artery diseases, possible role of HP infection in the pathogenesis of CSX is suggested. However well designed clinical trial studies are needed to confirm this preliminary result.