In this study, we compared renal function in patients after donor nephrectomy (DN) and radical nephrectomy (RN). We retrospectively reviewed 68 patients (mean follow-up 15 months), including 30 patients who had undergone DN and 38 patients who had undergone RN. The study was performed between April 2006 and July 2010 at a single institute. Patients were matched for age and co-morbidities (hypertension and diabetes mellitus). We calculated the estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease study group equation. Parameters studied included GFR (≥60 to <60 mL/min/1.73 m 2 ), serum creatinine (>2.0 mg/dL), metabolic acidosis (serum bicarbonate <22 mmol/L) and proteinuria (>30 mg). There were no significant demographic differences between the two study groups. After a mean follow-up of 15 months, low eGFR (<60 mL/min/1.73 m 2 ) was seen in 28% and 6.7% of patients in the RN and DN groups, respectively (P = 0.03). Similarly, proteinuria was seen in 21% vs 0%, P = 0.007, and de novo elevated creatinine was seen in 13% vs 0%, respectively P = 0.04; thus the changes were greater in the RN group. Our study shows that undergoing RN had a significantly greater risk of developing renal insufficiency and proteinuria compared with age-and co-morbidity-matched patients undergoing DN. We concluded that patients undergoing RN show a significantly greater risk of developing renal insufficiency and proteinuria compared with the patients undergoing DN.