Following an overview of previous studies, the present system of cannabis control in Britain is discussed. In view of increases in the consumption and supply of cannabis and the undesirable social consequences of enforcing the laws prohibiting cannabis, alternative controls are examined. Chapters detail the advantages and disadvantages of four major policy options. Retention of the present prohibitory system, but with changes in maximum penalties, is the first option examined. The present maximum penalties for simple possession are judged higher than necessary for deterrent effect. Decriminalization, the second option, assumes that the source of supply would be lawful cultivation of small amounts of cannabis for personal consumption. Decriminalization might reduce the illicit traffic and eliminate commercial pressure to promote and sell cannabis. Also, people who wished to use the drug could do so without commiting a criminal act. Licensing, the third option, would permit moderate use by adults without increasing availability. Also, it would discourage excessive consumption and reduce the attractions of the illicit market by providing a legal supply source. The final option, legalization, might encourage more use of cannabis, but this would depend on unpredictable changes in taste and fashion. Appendixes contain 11 relevant papers commissioned by the study group; individual papers contain footnotes, tables, and references.