Leigh syndrome (LS) is an inherited mitochondrial encephalopathy associated with gene mutations of oxidative phosphorylation pathway that result in early disability and death in affected young children. Currently, LS is incurable and unresponsive to many treatments, although some case reports indicate that supplements can improve the condition. Many novel therapies are being continuously tested in pre-clinical studies. In this review, we summarize the genetic basis of LS, current treatment, pre-clinical studies in animal models and the management of other mitochondrial diseases. Future therapeutical strategies and challenges are also discussed.