The syndrome of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) is a multisystemic disorder associated in most of the patients with an A to G transition at nucleotide position 3243 in the transfer RNA (tRNA)Leu(UUR) (A3243G) of the mitochondrial DNA. This syndrome is characterized by the preponderant involvement of skeletal muscle and central nervous system, but urinary or gastrointestinal symptoms are seldom documented. Here we report an unusual case of a 52-year-old woman with a clinical phenotype characterized by encephalopathy, left hemiparesis, urinary retention and gastrointestinal pseudo-obstruction. She had the classical A3243G mitochondrial DNA point mutation of MELAS syndrome. We also present a clinically heterogeneous multigenerational pedigree with several affected members in the maternal lineage.