Background and objectives: Treatment of spasticity poses a major challenge given the complex clinical presentation and variable efficacy and safety profiles of available drugs. We present a systematic review of the pharmacological treatment of spasticity in multiple sclerosis (MS) patients. Methods: Controlled trials and observational studies were identified. Scientific evidence was evaluated according to pre-specified levels of certainty. Results: The evidence supports the use of baclofen, tizanidine and gabapentin as first-line options. Diazepam or dantrolene could be considered if no clinical improvement is seen with the previous drugs. Nabiximols has a positive effect when used as add-on therapy in patients with poor response and/or tolerance to first-line oral treatments. Despite limited evidence, intrathecal baclofen and intrathecal phenol show a positive effect in severe spasticity and suboptimal response to oral drugs. Conclusion: The available studies on spasticity treatment offer some insight to guide clinical practice but are of variable methodological quality. Large, well-designed trials are needed to confirm the effectiveness of antispasticity agents and to produce evidence-based treatment algorithms.