Includes bibliographical references.

Selective mutism is a severe behavioral disorder that begins in childhood and whose essential characteristic is that children who present prevent or inhibit persistently speech in social situations that are initially targeted and progressively can go generalizing to finish in total silence, ie in avoiding or inhibiting speech to anyone and in any situation. In most cases, the onset of inhibition of speech usually coincides with the occurrence of a more or less abrupt and prolonged change in which children move from a familiar and safe environment (the family) to another unknown and uncertain ( kindergarten, kindergarten, school, prolonged hospitalization, change of residence, etc.). Despite the relevance of this disorder, the confusion that often results diagnosis and ignorance that still exists on evaluation and treatment justify the publication of this work.