There have been a few repots that serum immunoglobulins are increased in Perthes' disease suggesting possible immunological involvement in the pathophysiology of the disease. Joseph(1991) suggested that the raised IgM concentrations might be related to complications of Perthes' disease such as striking reduction of movement, fixed deformities and striking reduction of movement, fixed deformities and chondrolysis and that immunological mechanisms might be implicated in the mediation of some of the changes in Perthes' disease. More studies are necessary to prove the results. The purpose of this study is to detect if there is a true increase of serum immunoglobulins in Perthes' disease.