BACKGROUND Intrapulmonary shunting (IPS) is frequently observed and causes hypoxaemia in liver cirrhosis. This study investigated the prevalence, predictors of reversibility and the effect of living-related liver transplantation (LRLT) on IPS using contrast echocardiography in patients with end-stage biliary atresia. METHODS Fifty consecutive patients with biliary atresia were examined for IPS using contrast echocardiography before and after LRLT until IPS disappeared. The severity of IPS was classified into five grades according to the extent of contrast in the left ventricle (0, none; 1, trivial; 2, apparent; 3, complete but less than in right ventricle; 4, as dense as in right ventricle). RESULTS Thirty-two patients (grade 1, n = 15; grade 2, n = 7; grade 3, n = 4; grade 4, n = 6) had IPS before LRLT. Forty-four patients have survived for 9-26 months after LRLT. Among patients with grade 3 or 4 IPS (n = 8), there was a significant correlation between age at LRLT and the duration of IPS persistence after LRLT (P = 0.044). CONCLUSIONS IPS takes longer to disappear in older children than in younger ones, but always disappears eventually. LRLT is an effective treatment for biliary atresia with IPS. Presented to the 31st annual meeting of the Pacific Association of Pediatric Surgeons, Maui, Hawaii, June 1998