MELAS is an acronymfor the convergence of mitochondrial myopathy, encephalopathy lactic acidosis and stroke Hke episodes. It was described by Pavlakis et al. in 1984.This is a genetic disease caused by mutations in the maternal mitochondrial genome, affecting the adenosine triphosphate (ATP) synthesis. The mutations have heteroplasmic loads on different tissues, which could specially involve those highly energy-dependent such as muscles, brain and CNS tissues. We describe a 33 year oíd female presenting migraine headaches associated to stroke-like episodes, related to an infection. Neurological manifestations include language and visual disturbances. The magnetic resonance imaging (MRI) showed low-intensity áreas, predominantly in the temporal, parietal and occipital left lobes. She further presented a status epilepticus. The complementary study shows elevated basal and post exercise lactic acidosis, ragged red fibers in the muscle biopsy, and the mutation ofA3243G in the mitochondrial genome. Her asymptomatic mother and sister showed ragged red fibers in muscle biopsy. The patient showed clinical and radiological features improvement, maintaining non epileptic slow focal occipital discharges in the electroencephalogram. The assumption is that this mitochondrial disorder could be morefrequent than detected in our médium, given that a significant number of women could be just asymptomatic bearers (Hke the patient's mother and sister). This pathology should always be assessed in patients less than 40years ofage with strokes, regardless whether they havefamily history with the disease