Tremor is the most common involuntary movement disorder. It is differentiated from other involuntary movement disorders, such as chorea, athetosis, ballismus, tics, and myoclonus, by its repetitive, stereotyped, movements of a regular amplitude and frequency. Tremor can be defined as an involuntary, rhythmic, periodic, mechanical oscillation of a body part. Since small-amplitude tremors may not be visible to the naked eye and may only be detectable by sensitive recording devices, amplitude of the tremor is therefore not critical to the definition. Accurate diagnosis of tremor is important because appropriate treatment depends on the accuracy of the clinical diagnosis. This article reviews the classification and management of tremor.