Spasmodic dysphonia is a task-specific dystonia affecting the laryngeal muscles, resulting forced, strained voice. The pathophysiologic mechanism is not fully understood. We experienced a patient with epilepsy developed transient spasmodic dysphonia during valproic acid monotherapy. The spasmodic dysphonia resolved with dose reduction of valproic acid. Change of neurotransmitters, such as GABA in basal ganglia or blockade of sodium channel is possible mechanism in our case of drug-related spasmodic dysphonia.