The aim of this study was to determine usefulness of measurements of maximal systolic velocity of the hepatic artery with Doppler ultrasonography in the diagnosis of venoocclusive disease (VOD) after hematopoietic stem cell transplantation. We prospectively obtained 5 sonograms per patient: pretransplantation, day + 1, + 7, + 14, and + 28 on 36 nonconsecutive children who underwent hematopoietic stem cell transplantation. We examined the hepatic artery, the portal, hepatic and splenic veins, the thickness of the gallbladder wall, the presence of ascites, and the liver and spleen size. The diagnosis of VOD was based on clinical and laboratory data. Patients were divided into 2 groups: those with VOD (n=18) and those without VOD (n=18). The variance of 2 groups was analyzed. V-max of the hepatic artery had a strong correlation with clinical VOD diagnosis (P<0.001). There was no statistically significant difference in the other Doppler parameters. The results of our study showed that the measurement of V-max of the hepatic artery can provide important support in the diagnosis of VOD and can be useful in the follow-up of treatment response.