Introduction: One of the most important and progressive kidney diseases is renal tumors, and the most common renal tumor is renal cell carcinoma (RCC). Objectives: This study aimed to examine the renal masses and investigate the relationship between different tumor characteristics, such as their type and degree, with different factors such as age and gender. Patients and Methods: In this retrospective and cross-sectional study, all the patients who underwent radical or partial nephrectomy in Namazi and Ali Asghar hospitals in Shiraz from 2013 to 2017 were investigated. The renal mass pathologies of patients were examined and collected data were analyzed using SPSS-18. Results: A total of 381 cases were studied. 63.8% of them were male and 36.2% were female. The ratio of men to women was 1.76. The mean ages of women and men were 52.89 and 56.34, respectively. Regarding the type of tumor, RCC tumors were the most common (69%), which the clear cell carcinoma was the most common RCC (59%), next in line were oncocytoma, angiomyolipoma, transitional cell carcinoma (TCC), chronic pyelonephritis, primitive neuroectodermal tumor (PNET), and others. Conclusion: The results of this study showed that the frequency of benign renal masses in women is twice as high as in men. The types of tumors types were significantly different in both genders in comparison to each other. The incidence of clear cell carcinoma, the most common type of RCC, is more noticeable in older patients than younger ones. The type of tumor and its invasive behavior make the physicians perform partial nephrectomy in women more than men.