OBJECTIVES: We aimed to evaluate outcomes after Kawashima procedure with special regard to the development of pulmonary arterio-venous malformations. METHODS: All patients who underwent Kawashima procedure between 1992 and 2022 were reviewed. RESULTS: Twenty-one patients underwent Kawashima procedure at a median age of 14.5 (interquartile range, 8.4-40.4) months. There were no hospital deaths and 2 late deaths. Survival after Kawashima procedure at 5, 10, and 15 years was 90.5, 82.9, and 69.1%, respectively. It was 100% at 10 years for children 9 months old or younger at Kawashima procedure, compared with 77.0% for older children (p = 0.281). Hepatic vein incorporation was achieved in 16 patients (76.2%) at a median age of 3.3 (2.7-13.8) years and at a median interval of 2.6 (1.9-8.6) years. Survival after hepatic vein incorporation at 5, 10, and 15 years was 92.3, 83.1, and 55.4%, respectively. Pulmonary arterio-venous malformations developed in 4 patients after Kawashima procedure, which improved after hepatic vein incorporation in 3 patients. Of 4 patients who developed pulmonary arterio-venous malformations after hepatic vein incorporation, 2 patients died, and 2 patients survived. All of them had bilateral superior vena cava and hepatic venous flow was excluded in one lung as the cause of pulmonary arterio-venous malformations. CONCLUSIONS: Kawashima procedure could be performed with low operative risk on a patient aged less than 9 months. Despite the current early Kawashima and subsequent hepatic vein incorporation strategy, the incidence of pulmonary arterio-venous malformations did not decrease. Therefore, leaving antegrade pulmonary blood flow at Kawashima procedure is recommended.