A 70-year-old women presented classical CEFOM1 phenotypes such as bilateral ptosis and external ophthalmoplegia, but also progressive cerebellar ataxia, carrying a previously reported heterozygous missense mutation of KIF21A p.Arg941Gln. The present case is the first report of CFEOM1 showing cerebellar atrophy with hypoperfusion, mainly of the vermis, indicating that cerebellar function should be carefully evaluated in CFFOM1 patients.