Arthritis represents the most common complication of psoriasis, affecting a substantial proportion of patients. Various clinical manifestations are recognized with different prognoses. The clinical spectrum of psoriatic arthritis has been recently extended by newly described entities such as pustulosis palmoplantaris with osteoarthritis sterno-clavicularis and psoriatic onycho-pachydermo-periostitis. Besides methotrexate, cyclosporine has emerged as the drug of choice for the treatment of psoriatic arthritis, since it influences both cutaneous and arthritic manifestations of the disease. New immunosuppressive drugs, such as tacrolimus (FK 506), offer therapeutic promise. Future progress will depend on new insights into the pathogenesis of psoriatic arthritis.