The aim of this research was to identify the efficiency of a program of brief intervention for the decrease of the levels of anxiety in population deprived of the freedom. The research was shaped with 39 persons distributed in two groups, an experimental group (20 participants) and a group control with waiting-list (19 participants). For this research a quasi experimental design was in use and the participants were persons who entered for the first time to a penitentiary center who demonstrated agree in taking part voluntarily in the investigation. The instrument used to measure the levels of anxiety was the Questionnaire of Anxiety State - Feature STAI of Spielberger and Cols (1994). The results of the investigation demonstrate that the treatment applied to the experimental group obtained significant results in favour of the decrease of the levels of anxiety in the subjects deprived of the freedom.