Objective: To evaluate the results of extended calico-pyelo-nephrolithotomy through a vascular plane between posterior-inferior renal segments for the treatment of complex staghorn stone regarding stone-free rate, blood loss and kidney function. Patients and methods: All patients with complex branching and multiple renal calculi undergoing extended calico-pyelo-nephrolithotomy through avascular plane between posterior-inferior renal segments over 2.5 years were studied prospectively.