The classification of immune-mediated demyelinating polyneuropathies has become more complex in recent years. Initial definitions of chronic inflammatory demyelinating polyneuropathy (CIDP) were often broad enough to include almost any acquired polyneuropathy with demyelinating features. However, subdivision of acquired demyelinating polyneuropathies into different categories seems justified because 1) several distinct clinical syndromes have been identified, 2) characteristic and distinctive patterns of serum antibody binding are associated with each specific clinical syndrome and, 3) the syndromes respond differently to immune modulating treatments (Table 1). Larger series and controlled trials will be necessary to determine the therapeutic regimens that optimize the benefit:risk considerations for patients with these syndromes.