We describe a patient with a chronic, symmetric, monophasic, acquired, pure motor, demyelinating polyneuropathy. Electrodiagnostic studies showed the presence of multifocal conduction blocks in motor nerves at sites not prone to compression. A sural nerve biopsy was normal. The patient responded to immunosuppressive therapy and plasma exchange. We postulate that this disorder is an unusual variant of chronic inflammatory polyradiculoneuropathy.