INTRODUCTION AND OBJECTIVES: The S.T.O.N.E. nephrolithometry was previously developed to quantitate stone complexity and predict outcomes of PCNL. We sought to assess the ability of nephrolithometry score to predict perioperative variables in a multicenter database of patients undergoing PCNL. METHODS: We performed a multicenter review of patients undergoing PCNL. Preoperative CT images were reviewed and S.T.O.N.E. score was assigned to each patient. The association of S.T.O.N.E. score with patient demographics, stone characteristics and surgical outcomes was performed. RESULTS: Total of 706 patients were included in the analysis. The mean overall nephrolithometry score was 8.2 (range 5–13). Overall complication rate was 18%. Bleeding and sepsis were the most frequent complications. S.T.O.N.E. score was significantly associated with overall complication rate (P = 0.008), EBL (P = 0.001), and operative time (P < 0.001), and length of stay (P = 0.016). For each point increase in the score there is a 12.6mL increase in EBL. For each point increase in the score there is a 10.7 min increase in OR time. In risk stratification, medium-risk patients (8–10) and high-risk patients (11–13) had significantly higher EBL and OR time compared to low-risk patients with 5–7 scores (mean EBL 139, 197 and 134, OR time 132, 170 and 102, respectively, p = 0.001). Scoring system was not predictive of transfusion rates and fluoroscopy time in this cohort. CONCLUSIONS: Our multicenter data demonstrated that S.T.O.N.E. nephrolithometry accurately predicted surgical outcomes following PCNL, including overall complications, EBL and operative time. The scoring system obtained from computed tomography imaging may be effectively used in preoperative patient counseling and prediction of PCNL outcomes.