Spasticity is a major health problem for patients with a spinal cord injury (SCI). It limits their mobility and affects their independence in activities of daily living (ADL) and work. Spasticity may also cause pain, loss of range of motion, contractures, sleep disorders and impair ambulation in patients with an incomplete lesion. The effectiveness of available drugs is still uncertain and they may cause adverse effects. Assessing what works in this area is complicated by the lack of valid and reliable measurement tools. The aim of this systematic review is to critically appraise and summarise existing information on the effectiveness of available treatments, and to identify areas where further research is needed.