Familial recurrent plexopathy related to tomacular neuropathy is only the localized expression, with a familial predisposition, of a more diffuse disease. Such are the conclusions we drew from a study of 3 cases, in 2 families, of recurrent tomacular brachial plexopathy. In all 3 cases the condition was transmitted by the mother as an autosomal dominant trait. Biopsy of a sensory nerve was performed in 2 cases and showed, in one, typical images of myelinic degeneration at various stages, corresponding to the formation of tomacular tickenings. Tomacular brachial plexopathy must be distinguished from hereditary amyotrophic neuralgia.