Psoriatic arthritis is an inflammatory arthritis associated with psoriasis, which is usually negative for rheumatoid factor. The disease displays a wide spectrum of articular and periarticular features which may progress with time. Although psoriatic arthritis was thought to be a benign condition, it is now clear that up to 20% of patients progress to significant joint damage and functional disability. Recently, several predictors for progression have been described and suggest the need for earlier, more aggressive, use of therapy in these patients. The ideal treatment for psoriatic arthritis is unclear, and few randomised controlled trials have been reported to date in this condition. Prospective evaluation of the treatment of early disease is now required to assess the effect of current and future therapies on the clinical, radiological and functional outcomes of this condition.