Introduction: Gorham’s disease is a rare musculoskeletal disease which causes progressive osteolysis and is characterized by massive bone destruction due to proliferation of vascular elements along with a great number of osteoclasts. The etiology of the disease is unknown. Gorham’s disease is essentially rare in the forearm bones. As far as we know, only 2 cases of Gorham’s disease of the forearm have been reported with 1 of them in the radius and the other starting in the radius and spreading to the lower portion of the humerus. Case Presentation: This case report shows that Gorham’s disease may affect the ulna primarily and spread to adjacent bones despite the fact that there are no such reports in the literature. Conclusions: Gorham’s disease has several manifestations as primary bone involvement. As in this rare case the ulna may be affected first and then the disease may spread to adjacent bones. More studies are needed to better recognize the behavior of this rare disease.