Familial Mediterranean fever (FMF) is an autosomal recessive disease characterized by self-limited attacks of fever and polyserositis. Articular involvement in early-onset FMF is a common finding characterized by non-erosive, generally asymmetric monoarthritis in large joints. Protracted FMF arthritis was reported in 2.6% of Turkish patients. An 8-year-old female who has a history of FMF for 5 years applied to our hospital with complaints of persistent swelling and pain of her left knee for 8 months. The patient had been tried to be managed with non-steroidal anti-inflammatory drugs as well as intra-articulary steroids and colchicine. However, arthritis and acute phase response persisted. With sulphasalazine, complete recovery was achieved. It is our belief that sulphasalazine can be a choice of medical treatment in protracted FMF arthritis.