The clinical observations in five patients, of a family of catalan origin (NE of Spain), affected with Machado-Joseph disease are reported. The pedigree showed the presence of 22 members affected (15 men, 7 women) over six generations. The symptoms and signs were variable among the patients and also variable in a same patient during the course of the disease. However, the main neurological alterations were ataxia, akinesia, distal amyotrophy, progressive external ophthalmoplegia, facial and lingual fasciculations and bulging eyes. The neuropathological examination performed in one patient disclosed degeneration of the posterior and spinocerebellar tracts in the spinal cord, marked nerve cell loss in Clarke's column and anterior horns and axonal degeneration of the peripheral nerves, in addition to nerve cell loss in the nuclei of the III, IV and VII cranial nerves and neuronal depletion in the substantia nigra. No other structures, including the striate complex and dentate nucleus, were significantly affected.