INTRODUCTION AND OBJECTIVES: Obesity and hyperlipidemia are pro-inflammatory states that may increase renal stone formation. Statins, on the other hand, possess anti-inflammatory and anti-oxidative properties, and animal models on urolithiasis have shown that statins reduce renal tubular injury and inhibit crystal formation. Therefore, statin intake may reduce stone risk in clinical practice, but due to the lack of literature on this idea, we sought to determine statins' impact in a large community based cohort of patients.METHODS: We queried our Institution's Electronic Data Warehouse for all patients who were seen for an office visit, and diagnosed with hyperlipidemia during enrollment from January 2009 until December 2011. New statin prescriptions and new stone development were obtained from enrollment until June 2015. Demographics, stone risk factors, thiazide, potassium citrate intake and follow-up serum values for lipids and total cholesterol (TC) were recorded.RESULTS: In total, 101,259 patients met inclusion criteria, and 47.8% received a statin prescription during the study period.Patients not prescribed statins were significantly younger (51.9 vs. 60.7 years) and less obese (28.1 vs. 29.2 kg/m 2 , both p < 0.01). On follow-up, mean LDL and TC levels were significantly lower in the statin compared to the no statin group, suggesting compliance with medications. On univariate analysis (Table 1), non-stone formers who were statin users were significantly less likely to develop new stones compared to non-statin users (3.8% vs. 4.7%, p<0.01), and this protective effect was more dramatic among recurrent stone formers. Multivariate analysis (Table 2) adjusting for race, BMI, gender and comorbidities confirmed the protective effect of statins on new stones (OR ¼ 0.57, p<0.01). Likewise, on multivariate analysis, the protective effect of statins was greater in recurrent stone formers (OR ¼ 0.53, p<0.01).CONCLUSIONS: Our data substantiates previous work suggesting that statins are protective against renal stone formation. Their protective effect is greater among recurrent stone formers compared to stone naive patients.