The new text of the Swiss penal code, which entered into effect at the beginning of 2007, has many incidences on the practice of the psychiatrists realizing expertises in the penal field or engaged in the application of legal measures imposing a treatment. The most notable consequences of this text are, on the one hand, a new definition of the concept of penal irresponsibility which is not necessarily any more related to a psychiatric diagnosis and, on the other hand, a new definition of legal constraints that justice can take to prevent new punishable acts and which appreciably modifies the place of the psychiatrists in the questions binding psychiatric care and social control.