We report a case of symptomatic ecchordosis physaliphora (EP) in a 34-year-old woman who presented with progressive diplopia due to palsy of the left sixth cranial nerve. Repeated magnetic resonance imaging (MRI) disclosed typical characteristics of a congenital EP lesion with compression of the left abducens nerve presumably because of a secondary herniation of the arachnoid mater. We performed an augmenting combined recess resect procedure on the left eye. No progression of the lesion was observed over a period of 5 years. For differential diagnostics an EP has to be distinguished from skull base tumors, such as chordoma and chondrosarcoma.