This small pilot study examined the use of intraarticular methylprednisolone in hemophilic synovitis. Nineteen joints in ten adult hemophiliacs were studied. There was subjective improvement at 24 hr following injection in 79% of joints injected, and the improvement persisted up to 8 wk in 58%. The number of hemarthroses decreased following intraarticular steroids (mean of 7.7 bleeds in the 8 wk prior to injection versus a mean of 1.9 bleeds in the 8 wk following injection). Similarly the amount of clotting factor used for the injected target joint decreased from a mean of 7,616 units to 2,315 units postinjection (p less than .001). Improvement correlated with presence of synovitis but not with radiologic stage of the joint. Aspirated synovial fluids were analyzed and showed characteristics consistent with low-grade inflammation. These preliminary observations suggest that intraarticular corticosteroid injection may be a useful therapeutic tool in the medical management of hemophilic arthropathy.