We examined the Golgi apparatus (GA) of motor neurons of patients with ALS and in mice models of ALS by immunohistological method using antiserum against MG160 and against components of the trans-Golgi network (TGN46). The GA of half of the remaining spinal cord motor neurons of patients with sporadic ALS showed fragmentation, where the GA were dispersed or fragmented into numerous small, isolated elements. The GA of Betz cells in sporadic ALS were fragmented similar to that of anterior horn cells, and the GA of spinal cord motor neurons of those with familial ALS and of those with ALS with basophilic inclusions were fragmented or diminished. The GA in the majority of the motor neurons contained Bunina bodies, basophilic inclusions and superoxide dismutase 1 (SOD1)-positive aggregates were fragmented. The motor neurons in transgenic mice expressing G93A mutation of the SOD1 gene showed the fragmentation of the GA months before the onset of paralysis. These findings suggest that the fragmentation of GA may be related to the neuronal degeneration in patients with ALS.