In addition, extralegal variables such as religiosity and the number of friends using marijuana are important mechanisms of social control. Self-report data came from 631 subjects in Washington, D.C., and 551 subjects in Omaha, Neb. who were part of a larger, national survey. The study compared these two jurisdictions because of their different statutory penalties for using marijuana. The penalty in Washington, D.C., was a term of confinement of up to 1 year and a fine of up to $1,000, whereas the comparable penalty in Omaha was a maximum of 7 days in jail with no fine. In both jurisdictions, legal factors were significantly related to marijuana use or nonuse. Although the legal variables accounted for a larger proportion of variance in the high penalty area, direct legal threats of arrest and jail were a greater inhibitor of marijuana use in the low penalty area. This difference may have been due to the more vigorous and conscious enforcement of the Nebraska law. In Washington, D.C., arrests for marijuana use and possession tended to result from an officer's viewing the violation than from some prior investigation. Jurisdictional comparisons represent a reasonable test of ideas about forms of social control, but they should be informed with data concerning crime patterns, methods of legal intervention, and other correlates of crime. Data tables, notes, and a list of 23 references are provided.