Chronic thyreotoxic neuromyopathy was observed in four patients. The first two cases were observed in a 43-year-old woman and a 60-year-old man. In the man, muscle disorders were the first manifestation and in the woman they were preceded by Graves' hyperthyroidism. Muscle signs were seen as functional impotency with amyotrophy of the girdle which was major in the man and minor in the woman. In a third case, a pyramidal syndrome was associated with polyneuropathy in a 28-year old man. Laboratory tests showed hyperthyroidism, neurological signs regressed with antithyroid drug therapy. A fourth case presented as thyrotoxic hypokaliemic periodic palsy in a 37-year-old man who had loss 12 kg over a two month period after a psychological stress. This man then experienced two acute episodes of hypokaliemia and hypotonic tetraplegia. These signs were linked to Graves' hyperthyroidism. Clinical course was good under carbimazole and then radioactive iodine. These four cases illustrate the reality of thyrotoxic neuromyopathies in black Africans.