Objective: To compare the PCNL surgical results performed in modified supine position with those executed in the standard prone position. Study Design: A prospective randomized controlled trial. Place and Duration: In the Department of Urology, Sindh Institute of Urology and Transplantation, Karachi for one year duration from January 2020 to December 2020. Methods: 186 patients who underwent percutaneous nephrolithotomy were selected for the study, who were randomized into 2 groups of 93, in the first group PCNL was done in modified Supine position and the other was planned for Prone PCNL. Surgery time, number of punctures, complications, radiation time, stay in hospital and stone-free index were compared. Results: There was no variance among the two groups in the number of punctures, number of calculi and complication rates. However, the modified supine group had shorter mean time of radiation, surgery time, and hospital stay. Conclusion: Modified supine PCNL in the supine position has a much shorter exposure of radiation and operation time, shorter hospital stay, and is just as safe as traditional prone PCNL. Key words: percutaneous nephrolithotomy, PCNL, supine position, renal stones.