Asynchronous bilateral renal cell cancer has been associated with poorer survival than synchronous bilateral disease, presumably due to its large tumor burden. In this series, 23 patients (14 male, 9 female; age, 39 to 76 years; median age, 59 years) with synchronous tumors and 17 patients (13 male, 4 female; age, 38 to 75 years; median age, 63 years) with asynchronous tumors underwent definitive surgical treatment (nephrectomy, in vivo and ex vivo partial nephrectomy with autotransplantation). Duration of follow-up ranged from 2 to 20 years (median, approximately 5). The 5-year cause-specific survival rates were approximately 80% and 84% for synchronous and asynchronous disease, respectively (nonsignificant difference). These data provide additional clinical evidence that disease outcome for asynchronous tumors can be as favorable as that for synchronous tumors with definitive surgical treatment. Diligent follow-up after operation for unilateral disease is necessary to allow for timely surgical information in asynchronous disease.