Purpose To compare the effects of two border-age groups: young adults and octogenarians on survival of sporadic renal cell carcinoma (RCC). Methods We reviewed the records of 1619 patients that underwent radical or partial nephrectomy due to RCC between January 2004 and December 2018 in two high-volume centers. Patients were divided into two groups based on their age: <= 40 years old (group 1) and >= 80 years old (group 2). We analyzed the demographic, clinical and histological features of the groups and performed univariable and multivariable Cox regression analyses to evaluate predictors associated with survival. Results Median ages of patients were 35.5 years and 82 years in group 1 (n = 90) and group 2 (n = 55), respectively. Radical nephrectomy rate was statistically higher in group 2 (p = 0.004). Median follow-up was 72 (11-192) months in group 1 and 30 months (5-103) in group 2 (p < 0.001). The 5-year (90.2% vs. 80.2%) and 8-year (84.8% vs. 60.2%) overall survivals (OS) of the groups were statistically different (p < 0.001). Patients in group 1 demonstrated a 5 and 10-year cancer-specific survival (CSS) of 90.2% and 84.7%, whereas these rates were 82.4% and 54.9% for group 2 (p < 0.05). We found that higher hemoglobin drop (HR: 1.497), presence of sarcomatoid differentiation (HR: 4.307), high-stage disease (HR: 2.704), and metastasis detected in the follow-up (HR: 12.805) were independent risk factors that shortened OS (p < 0.05). Conclusion Sporadic RCC was associated with a more favorable CSS and OS in young adults compared to the octogenarians. Although two border-age groups had similar pathologies, they have different prognosis and survival rates.