Kearns-Sayre syndrome is an extremely rare mitochondrial myopathy, characterised by retinitis pigmentosa associated with progressive external ophthalmoplegia. Cardiac conduction abnormalities are common and range from bundle branch block to third degree atrioventricular block. Generalised degeneration of the central nervous system has also been reported. We describe the anaesthetic management of a child afflicted by this syndrome. The major anaesthetic complication in this disease is sudden third degree atrioventricular block which may lead to death in the absence of an artificial cardiac pacemaker.