Objective. To assess whether cigarette smoking had an effect on superior mesenteric artery postprandial blood flow. Methods. Forty-six subjects were studied in 3 groups with Doppler sonography. Group A consisted of nonsmokers; groups B and C consisted of smokers. In group B, subjects were allowed to smoke cigarettes postprandially, whereas in group C, postprandial smoking was prohibited. A baseline Doppler evaluation was performed in the fasting state, and consecutive Doppler evaluations were performed postprandially with 30-min intervals for 120 minutes. Doppler sonographic measurements of the superior mesenteric artery including peak systolic and end-diastolic velocities, resistive index, and diameter, were calculated. Statistical analysis was performed by analysis of variance. Results. All groups showed significant changes with time for all parameters (P < .001 for all). The changes in time were significantly different at 90 and 120 minutes for peak systolic velocity, at 90 minutes for end-diastolic velocity, and at 120 minutes for diameter between groups. Group B had the greatest differences. Compared with group A, changes in peak systolic velocity at 90 to 120 minutes were significantly lower in group B (P = .007 and .006, respectively), and compared with groups A and C, changes in end-diastolic velocity at 90 minutes (P = .006 and .004, respectively) and diameter at 120 minutes (P = .007 and .011, respectively) were significantly lower in group B. Conclusions. Smoking immediately after meals was associated with a superior mesenteric artery blood flow increase that was lower than expected, which may explain the belief that smoking reduces body weight. Postprandial smoking may have undesired results in patients with chronic intestinal ischemia.