Many poststroke survivors develop spasticity. Spasticity is usually associated with other neurologic impairments, in particular paresis, which complicate the evaluation of its consequences and of treatment outcomes. The diagnosis and the assessment of spasticity are based on clinical examination, in particular resistance to passive movement and abnormal involuntary muscle contraction. Nonpharmacologic and pharmacologic treatments are commonly combined to manage spasticity, based on prespecified goals. There is evidence supporting the effectiveness and safety of most medications commonly used to treat spasticity; however, more evidence is needed regarding functional outcomes and the impact of combining treatment modalities.