This paper analyzes social control in a prison at a time when many authors see it as an open institution. In 2003, 36 inmates in three Canadian penitentiaries were interviewed about their experiences in prison. The results indicate that inmates, despite a normative system of citizen rights in prison, are still controlled by subjective power. In a correctional context that favors actuarial evaluations and the expert’s interpretation, inmates feel discredited and reduced to case management work. As such, it appears that the best strategy to obtain a short-term release is to adopt “good behavior” and to respect implicit and official rules. In conclusion, the internal social control is not only very present, but also focused on strong and well-defined managerial practices.