High-dose chemotherapy with stem cell transplantation (SCT) is feasible for elderly patients and patients with renal insufficiency. However, the impact of treatment on this patient population is unclear. We evaluated 678 consecutive patients with multiple myeloma who underwent SCT at Mayo Clinic. The complete response rate, time to progression and overall survival was recorded. Patients were stratified according to age (< or =65 or >65 years) and serum creatinine value at the time of transplantation (< or =2 or >2 mg/dl). Patient age did not have an effect on any outcome measure. Creatinine level did not affect complete response rate and time to progression, but patients with creatinine levels above 2 mg/ml had a higher day-100 mortality rate and a shorter overall survival rate. Platelet engraftment was also significantly delayed for patients with renal insufficiency. Selected patients over age 65 years may have outcomes identical to that of younger patients. When compared with patients with creatinine levels less than 2 mg/ml, patients with elevated creatinine levels had similar response rates and time to progression, but their overall survival was inferior. Transplantation should be offered to selected patients over age 65 years or selected patients with creatinine elevation.