Previous studies demonstrated that iloprost improves the peripheral circulation. In this study, we examined, by Doppler sonography, portal flow velocity (cm/s) and volume (mL/min), and resistance index (RI) of visceral arteries in 23 patients before and after 7 days of iloprost infusion. Statistically significant hemodynamic changes were only seen in portal vein (pre-iloprost vs. post-iloprost treatment mean portal flow velocity and volume values: 23.9 cm/s vs. 29.0 cm/s, p < 0.001 and 1824.6 mL/min vs. 2294.4 mL/min, p < 0.001, respectively). On the other hand, the interlobar renal artery RI, reduced after iloprost treatment in most patients, was not statistically significant; conflicting results were obtained on the hepatic and mesenteric arteries. Our results indicate that iloprost significantly increases portal flow velocity and volume. The understanding of the mechanism through which iloprost plays a role in portal microcirculation could be useful for its new medical indications in liver hemodynamic disorders.