Background/Aims: To evaluate the effect of plasma exchange on renal function in patients with rapidly progressive renal failure secondary to multiple myeloma. Methods: The study was done through a retrospective chart review using a standardized form at a tertiary care centre in southwestern Ontario. Patients were included in the study if they had a diagnosis of multiple myeloma and rapidly progressive renal failure. Multiple myeloma was defined by a bone marrow aspirate >15% plasma cells plus one of the following: serum monoclonal paraproteins, monoclonal light-chain excretion, or lytic lesions. Patients were excluded if they had evidence of chronic renal failure or failed to complete three plasma exchanges. Twenty-six patients were reviewed; of these 24 were followed up to 1 year. All patients received hydration, standard chemotherapy, and plasma exchange. The plasma exchange volume was 50 ml/kg of 50% normal saline and 50% human serum albumin. Primary outcome measures included (1) prevention of acute dialysis and (2) prevention of progression from acute to chronic dialysis; secondary end points included (1) a decrease in creatinine of 25% or more within 3 months of the last plasma exchange and (2) survival at 1 year. Results: Sixteen of 24 patients, followed up to 1 year, did not require dialysis. Two patients required dialysis initially, but were able to come off dialysis after 3 months. Fourteen patients were alive at 1 year, 13 of whom were dialysis independent. Twelve of 13 dialysis-independent patients had a >25% reduction in creatinine at 3 months. Two patients were lost to follow-up after discharge and were not included in the analysis. Conclusions: This retrospective study suggests that plasma exchange may offer some benefit in preventing the initiation or continuation of dialysis in patients with rapidly progressive renal failure secondary to multiple myeloma. A randomized controlled prospective study is needed to determine whether plasma exchange should be recommended as a standard treatment for patients with rapidly progressive renal failure due to multiple myeloma.