In order to differentiate between the manifold phenomena of haemophilic arthropathy, and to treat them suitably, the author suggests a classification of haemophilic arthropathies. Qualitatively speaking, it is possible to differentiate between 6 forms of bleeders-joint: the virginal, restituted, acute, florid, latent and activated form. Quantitative subdivision is effected according to two criteria: the extent of actual destructive activity of the joint being one criterion of classification, the other one being the extent of permanent damage to the joint.