Abernethy malformation is a rare congenital vascular anomaly that results in an extrahepatic portosystemic shunt. In this case, an association between Abernethy malformation type II and IgA nephropathy, a kidney disease characterized by the presence of IgA deposits in the glomeruli, was described. The patient initially presented with proteinuria (0.8–2.1 g/day) and hematuria, and later developed hepatic encephalopathy. Vascular imaging confirmed the presence of a type II portocaval shunt. After laparoscopic partial shunt connection, there was a significant reduction in proteinuria to 0.19–0.29 g/day. This case suggests that portosystemic shunt may be a pathogenic factor in IgA nephropathy, and surgical correction of the shunt may result in renal improvement[2][3].