In February 1992, the handling of cases of mental disorder in the criminal justice system was modified by amendments to the Canadian Criminal Code. These changes are part of an important North America-wide debate on the criminalization of mental disorder. The usual assumption has been that the criminal justice system would take charge, in some significant manner, of persons with mental disorders, an undertaking in lieu of psychosocial or psychiatric treatment. The use of Criminal Code procedures with regard to these persons is an important element in any study of the dynamics involved. In this article, the author reviews the Criminal Code provisions from the perspective of the presumed relationships between the criminal justice and mental health systems and from the perspective of the transformations likely to occur in these relationships. Based on this perspective, the modifications to the Criminal Code will extend the interface between the two systems and, thus, potentially generate certain problems and confrontations. The author discusses these difficulties and presents several cases. Notes, references