A 67-year-old woman had frequent subacute ileus, hearing difficulty, muscle atrophy and stroke-like episodes. Computed tomography revealed multiple low-density areas, which did not correlate with the vascular supply, in the cerebral cortex. She had metabolic disturbance comprising lactic acidosis and elevated pyruvate level. Her skeletal muscle biopsy specimen showed ragged-red fibers, and mitochondrial DNA analysis revealed a point mutation at position 3243, findings consistent with MELAS. Examination of her small intestine revealed a necrotic zone and numerous abnormal large mitochondria in the smooth muscle cells, vascular media and endothelium, and intestinal ganglion cells. The cerebral cortex showed multiple microcystic necrotic foci in cerebral cortex. Cactus-like pathology resembling the changes associated with Menkes' kinky hair disease and torpedoes were observed in the cerebellar Purkinje cells. The intestinal dysmotility due to MELAS and cerebellar changes were presumed to be associated with a disturbance of copper metabolism.