We report a young woman presenting with "painful diplopia" caused by inflammation of external eye muscles affecting both eyes sequentially. Orbital MRI disclosed swelling, signal hyperintensity and enhancement of isolated eye muscles. Corticosteroid treatment led to a complete remission within a few days. The compiled data of a literature review enclosing 52 sufficiently documented patients diagnosed as orbital myositis is reported with respect to clinical features, laboratory findings, associated disease, value of imaging procedures (CT,MRI). Therapeutic aspects and differential diagnosis are reviewed.