The rationale for therapeutic plasma exchange (TPE) in acute polyradiculoneuropathy (APRN) is based on the presence of circulating antibodies which cause demyelination of the peripheral nerves. This study included 24 patients, most having a neurological defect of grade 4, classified into groups A and B. Group A was treated with immunosuppressive drugs only, while group B was treated by a combination of immuno-suppressive drugs and TPE. The average volume of plasma removed during a single TPE procedure was 2.95 L, and totalled 21 L overall.The efficacy of the TPE treatment was assessed on the basis of changes in the neurological deficit grade, and in electrophysiological parameters. It was shown that improvements were significantly better and faster in patients treated by a combination of immuno-suppressive drugs and TPE, and when TPE was started within the first 7 days after the onset of the disease.