515 Background: Previous reports describe that 20% of small renal masses (SRM) are benign and women are twice as likely to have benign pathology. In this study we further explore the association of baseline health and gender with SRM pathology. Methods: After IRB approval, retrospective chart review of patients who have undergone nephrectomy at Memorial Sloan-Kettering Cancer Center from 05/1998 to 10/2012 with final path ≤ 4cm and staged as pT1a if malignant. Tumor size ≤ 4cm was chosen to limit the tumor mass effect on renal function. Patients with solitary kidney, multiple and bilateral tumors, and history of prior renal surgeries were excluded. Collected data included age, gender, race, ASA class for medical co−morbidities which were divided into low (I−II) and high (III−IV), procedure, preoperative serum creatinine, eGFR, and final pathology. eGFR was calculated using the CKD−Epi formula. Preoperative Chronic kidney disease (pCKD) was defined as eGFR < 60 mL/min per 1.73 m2. Malignant pathologies were clear cell renal cell carcinoma (RCC), papillary RCC and chromophobe RCC whereas benign were oncocytoma, angiomyolipoma and other. Logistic regression analysis was performed to determine clinical factors associated with malignant SRM. Results: Our cohort consisted of 1726 patients with mean age 59.7 yrs. 61% (n=1045) were men, 90% (n=1,553) were white, 43% (n=736) had high ASA, 89% (1,540) underwent partial nephrectomy, 30% (n=525) had pCKD, 83% (n=1426) with malignant pathology and mean tumor size 2.5cm. On bivariable analysis patients with malignant SRM had a higher proportion of men (64.3 vs. 42.7%, p<0.001), high ASA class (43.8 vs. 37.3%, p=0.041) and larger tumors (2.6 vs. 2.3, p<0.001). There were no differences in age, race, mean eGFR or proportion with pCKD. On logistic regression analysis by gender factors associated with malignant pathology in women were high ASA class (OR 1.57, 95% CI 1.07−2.32) and tumor size (OR 1.48, 95% CI 1.20−1.81), and in men tumor size only (OR 1.33, 95% CI 1.06−1.67). Conclusions: Our results are in line with previous reports on the association of male gender and larger tumor size with malignant SRM. In addition we do show that among women those with poor health have a higher likelihood for having a malignant SRM.