Theoretical issues surrounding the effects and purposes of criminal laws are first explored, followed by an historical overview of Canadian narcotic drug laws and enforcement activities. A model for determining whether criminalization is increasing from both the official and social perspectives is outlined. To determine the social effects of punishment on individual cannabis users, this study selected 95 persons sentenced for the offense of simple possession between July and September 1974 in the Provincial Court of Metropolitan Toronto. Of the total sample, 87 percent were males and 68 percent were persons 21 years old or younger, which is representative of all cannabis cases prosecuted in 1974. Other characteristics of this group are detailed, such as education, employment, living arrangements, drug use patterns, and legal representation. The presiding judge was found to be the most important determinant of the case outcome. The process of becoming a cannabis criminal as described by these subjects covers the arrest circumstances, police behavior, and court appearance. The social impact of criminalization on these individuals at the time of sentencing is evaluated in terms of personal identity, social relationships, economic costs, attitudes toward the law, and loss of rights and privileges. A discussion of the benefits of criminalization concluded that it does little to deter cannabis use. The effects of a longer period of criminalization were explored through interviews with 85 respondents 1 year after their court appearance and sentencing. Unemployment, job changes, and involvement in criminal activities increased, but cannabis use persisted at moderate or high levels. The final chapter analyzes the implications of the study's findings for the user, the law, and society. The appendixes contain statistical tables, two case histories of cannabis offenders, and approximately 150 references. Footnotes and an index are provided.