The Authors report their experiences in Redon tube closed washing-drainage treatment of secondary septic arthritis in adults. This technique, used at an early stage as an alternative to needle drainage, does not require plaster immobilisation and has allowed a good residual function to be obtained. In case of absence of response to the treatment, it is considered inadvisable to persist; in such case the surgical approach with "functional treatment", and with or without combined synovectomy, is recommended.