Partial splenic embolization (PSE) was successfully accomplished in 10 of 11 children, aged 2-9, who had portal hypertension or variceal bleeding. Nine of the 11 children had undergone portoenterostomy (Kasai operation) for biliary atresia, and two had portal vein thrombosis. After embolization these children had a longer period of fever (mean = 23.7 days) and elevated white blood cell (WBC) count (above 10,000, mean = 13.6 days) than adults who have undergone the same procedure. The leukopenia and thrombocytopenia of hypersplenism were corrected by PSE in seven of eight children, and the condition of the eighth child improved. Among ten patients who had experienced episodes of variceal hemorrhage, the frequency of bleeding episodes was reduced from an average of 2.87 per year before PSE to 0.67 per year after PSE. There were no splenic abscesses and no other significant complications of the treatment. Ultrasound (US) evaluation after embolization demonstrated hypoechogenicity of the infarcted areas and tiny, linear echoes scattered throughout the spleen typical of postinfarction intravascular gas. All nine children who underwent follow-up Tc-99m sulfur colloid scanning showed evidence of splenic regeneration, though none has had recurrence of clinical symptoms. Splenic regeneration following PSE may occur more frequently in children than in adults.