Twenty-three joints in 14 cases of chronic synovitis were treated with intra-articular injection of 32 p-chromic phosphate, including 19 knee joints, one elbow joint with rheumatoid arthritis and 3 knee joints with degenerative arthritis that was recractory to medical treatment. Results of 23 joints evaluated at end of one year were excellent in 43.5$, good in 30.5%, .fair in 13% and poor in 13%. There was a good correlation between the radiographic stage of the joints and the response to treatment. Patients in stage 1 and 2 were more likely to have good to excellent response. Cur study shows that radiation synovectomy is a simple, safe and effective treatment than other managements for chronic synovitis