Diagnosing dystonia requires a solid understanding of the phenomenology of this movement disorder as well as successful classification and a systematic search for the etiology. We describe the current definition, classification, and methodology for reaching an accurate diagnosis. This review covers the most relevant clinical features of disorders where dystonia is present, emphasizing the affected genes most recently identified, as well as other pathophysiologic factors involved in the generation of this condition. Finally, advances in medical treatment and surgery for dystonia are discussed. Key words: antipsychotics, botulinum toxin, combined, deep brain stimulation, dopa-responsive dystonia, dystonia, focal, isolated, neurodegenerative, phenomenology, specific task, triggers