Hemophilic pseudotumor is a rare, but well-known, complication of hemophilia 
occurring in 1-2 % of individuals with a severe factor VIII or IX deficiency. 
The hemophilic pseudotumor is defined as an encapsulated hematoma that increases 
of volume progressively by episodes of recurrent hemorrhage; usually originate 
in soft tissues or in subperiosteal or intraosseous areas. Very seldom, patient 
with mild form of hemophilia present with intraosseous pseudotumor. This report 
describe an 11-year-old boy with mild factor IX deficiency (17 % of normal 
factor IX activity), who developed a pseudotumor of the femur.