Mitochondrial myopathies are heterogeneous group of clinical disorders that can affect multiple systems besides skeletal muscles. The mitochondrial abnormalities in the skeletal muscles are morphologically identified by the presence of characteristic Ragged-red fibers (RRF) in the cryostat sections of the muscle stained with modified Gomori's trichrome stain. In this retrospective study, clinical and histopathological features in six patients with mitochondrial myopathies have been analysed. The utility of histochemical methods in confirming the diagnosis of mitochondrial myopathy has been emphasised.