We report the clinical and autopsy findings of two patients with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS). The cases were unusual in that both patients presented with stroke-like episodes and neither patient had clinically evident myopathy, consequently in neither case was the correct diagnosis made during life. Despite the absence of myopathy clinically, at autopsy skeletal muscle showed the characteristic features of mitochondrial cytopathy. One of the patients, in addition to the features of MELAS, also had gastrointestinal involvement at presentation which was sufficiently severe to warrant surgery and a peripheral neuropathy.