Objective: To evaluate the feasibility, safety, and efficacy of three-step dilation in flank-free oblique supine modified lithotomy (FOSML) position in supine percutaneous nephrolithotomy (PCNL). Materials and Methods: A total of 79 patients underwent supine PCNL in the FOSML position between April 2018 and July 2019. Out of these patients 4 patients were excluded as they were operated on intravenous urography without prior NCCT KUB study and 1patient underwent additional surgery along with PCNL. Remaining 74 were considered eligible for inclusion in the study. Parameters evaluated for the study were stone characteristics; fluoroscopy time for renal access, total operating time, preoperative and postoperative hemoglobin concentrations puncture attempts, tract dilatation failures, complications, and transfusions. Results: Mean fluoroscopy access time was 131.28 seconds with an average stone size of 2.53 cm. Infracostal puncture was performed in 62 and the remaining 12 patients underwent supracostal access. Mean hemoglobin reduction was 1.27 gm %. Major complications were blood transfusion in 9 patients and ICD insertion in 1 patient. The mean duration of hospital stay was 71.52 hours. Conclusion: The Technique of three-step dilatation for supine PCNL in the FOSML position is safe, cost-effective, and offers shorter renal access time and operative time. This technique is an inexpensive alternative to other dilatation techniques