Intravenous 7S-immunoglobulins (IVIg) are made of intact human IgG from pooled plasma by using cold alcohol fractionation followed by further purification steps to remove complement-activating material. The half-life of IVIg in vivo is approximately 3 weeks. Favourable effects were reported in patients with myositis and multifocal motor neuropathy who did not respond to established immunosuppressive therapies, and in Guillain-Barre-Syndrome and chronic inflammatory demyelinating polyneuropathy. No definite recommendation can presently be made concerning their use in other neuromuscular disorders and in multiple sclerosis where the results of ongoing and future controlled studies have to be awaited. Some of the possible mechanisms of immunoglobulin efficacy have been delineated in animal models and tissue culture: anti-idiotypic suppression, down-regulation of B- and T-cell activation, blockade of Fc receptors on phagocytic cells, neutralisation of superantigen and complement mediated effects, down-regulation of cytokine production and neutralisation of cytokines. Few side effects have been reported to date. However, treatment is expensive when compared with established immunosuppressive therapies. The main risk consists of the transmission of infectious agents that can only be excluded if the manufacturing process is optimal. A broad and uncontrolled use of immunoglobulins in the treatment of neurologic disorders is discouraged.