Paroxysmal movement disorders are a heterogeneous group of syndromes that produce recurrent attacks of involuntary movements without loss of consciousness as their common feature. In this chapter a very short historical overview is given before discussing the current classification and diagnostic criteria of the three main types of paroxysmal movement disorders: paroxysmal kinesigenic dyskinesia, paroxysmal non-kinesigenic dyskinesia and paroxysmal exercise–induced dyskinesia. During the past two decades, a rapidly growing number of genes that cause paroxysmal movement disorders have been reported. This also challenges the current classification because many genetic forms of paroxysmal dyskinesia can be caused by mutations of the same gene. Nevertheless, a first clinical description and classification appears to be reasonable and important. The chapter also describes the episodic ataxias, along with their genetic background, as well as the non-genetic causes of paroxysmal movement disorders, which include vascular, structural, infectious, inflammatory and metabolic causes. The last part of the chapter deals with a proposed approach to a patient with paroxysmal dyskinesia in daily practice.