Tremor is defined as involuntary, rhythmic, and sinusoidal movement. The rate, location, amplitude, and constancy vary depending on the specific type of tremor and its severity. Etiologies and treatment of tremors differ according to the type of tremor. It is helpful to determine whether the tremor is present at rest, with posture-holding, with action or with intention maneuvers. Rest tremor is most typically present in patients with Parkinson's disease. Physiologic tremors and essential tremors are common forms of postural tremor. Intention tremor is typically present in cerebellar lesions. Associated neurological symptoms and signs are also helpful for differential diagnosis. Not all patients with hand tremor have Parkinson's disease. Rest tremor, bradykinesia, rigidity, and loss of postural reflex are cardinal signs of Parkinson's disease. Careful observation of the patient is the key point of diagnosis in patients with tremor.