Alpers syndrome was not clearly defined until the link between brain and liver disease was described. Alpers syndrome can now be clearly established as a disorder of oxidative metabolism related to mitochondrial dysfunction, and in most instances with an autosomal mode of inheritance. The symptoms and signs are discussed. The illness occurs in the first years of life with the sudden onset of intractable seizures associated with developmental delay, hypotonia, ataxia, cortical blindness, and hepatic failure, and death occurs within a short time. Treating the seizures with valproic acid can cause the rapid onset of liver failure and must be avoided. To establish a definite diagnosis, liver and muscle biopsies may be needed. The former shows bile duct proliferation with the evidence of cirrhosis, and the latter may support the involvement of the mitochondrial respiratory chain if there are ragged-red fibres. Genetic studies can show an association with mitochondrial DNA depletion and mutations in the polymerase gene. Cytochrome c oxidase deficiency has been demonstrated in some patients. Useful diagnostic tests include liver function tests, lactic acid levels in the blood and cerebrospinal fluid, electroencephalograms, computed tomography, and magnetic resonance imaging. The differential diagnosis will be from other forms of neuronal degeneration and disorders of mitochondrial function. There is no specific treatment, which must await further research into causes.