Background: Associated risk factors for renal cell carcinoma (RCC) include smoking, obesity, hypertension, and diabetes mellitus (DM). Studies on their role in Sri Lankan patients are sparse. The aims were to determine the risk factors for RCC in a cohort of Sri Lankan patients. Methods: A hospital-based case–control study was done in a teaching hospital from January 1, 2009, to December 31, 2015. The prospectively collected data included history of smoking, hypertension, DM, and body mass index (BMI). The controls were patients who were admitted after trauma and who required abdominal ultrasonography as part of routine assessment. The controls were accrued at a ratio of 1:2 and were age- and gender-matched. Chi-squared test was used, and P < 0.05 was considered statistically significant. Results: There were 178 patients with RCC. The mean age of patients with RCC was 56.9 years. Male to female ratio was 3.5:1. Forty-nine (27.5%) patients were < 50-year-old. 36.5% were asymptomatic and diagnosed incidentally by ultrasound scanning. Obesity (BMI > 30) (P < 0.01), DM (P < 0.05), and hypertension (P < 0.01) were significantly more common among the cases than in controls. There was no difference in the prevalence of smoking between the two groups (P > 0.5). Conclusions: Average age at the time of diagnosis of RCC in Sri Lankan patients is lower than the developed world, with a large proportion of patients being under 50 years. Obesity, hypertension, and DM are associated risk factors for RCC in Sri Lankan patients while smoking is not.