External ophthalmoplegia and ptosis are common manifestations of mitochondrial cytopathy, such as chronic progressive external ophthalmoplegia (CPEO). However, these symptoms and signs may also be presenting features of myasthenia gravis (MG). There are a few reports of CPEO with elevated acetylcholine receptor antibody (AchR-Ab). We report a case of AD-type CPEO with elevated acetylcholine receptor binding antibody. We confirmed a mutation on the SLC25A4 gene by molecular analysis.