BACKGROUND: Relative to radical nephrectomy (RN), partial nephrectomy (PN) performed for renal cell carcinoma (RCC) may protect from non‐cancer‐related deaths. The authors tested this hypothesis in a cohort of PN and RN patients.METHODS: The Surveillance, Epidemiology, and End Results‐9 database allowed identification of 2198 PN (22.4%) and 7611 RN (77.6%) patients treated for T1aN0M0 RCC between 1988 and 2004. Analyses matched for age, year of surgery, tumor size, and Fuhrman grade addressed the effect of nephrectomy type (RN vs PN) on overall mortality (Cox regression models) and on non‐cancer‐related mortality (competing‐risks regression models).RESULTS: Relative to PN, RN was associated with 1.23‐fold (P = .001) increased overall mortality rate, which translated into a 4.9% and 3.1% absolute increase in mortality at 5 and 10 years after surgery, respectively. Similarly, non‐cancer‐related death rate was significantly higher after RN in competing‐risks regression models (P < .001), which translated into a 4.6% and 4.5% absolute increase in non‐cancer‐related mortality at 5 and 10 years after surgery, respectively.CONCLUSIONS: Relative to PN, RN predisposes to an increase in overall mortality and non‐cancer‐related death rate in patients with T1a RCC. In consequence, PN should be attempted whenever technically feasible. Selective referrals should be considered if PN expertise is unavailable Cancer 2009. © 2009 American Cancer Society.