Internationally, where marijuana is illegal, users follow etiquette rules that prevent negative consequences of use. In this study, adherence to etiquette is hypothesized to reduce likelihood of marijuana-related police stop/search and arrest. Ethnographers administered group surveys to a diverse, purposive sample of 462 marijuana-using peer groups in several areas of New York City. Findings indicated that lack of etiquette was associated with dramatically higher likelihood of police stop/search or arrest only for users who were Black, male, and/or recruited from Harlem/South Bronx. If these users followed a few identified etiquette rules, their risk of police stop/search or arrest was comparable to that of other users. Implications are that etiquette represents an intentional conscientiousness about marijuana use. Groups that are specially targeted for anti-marijuana enforcement can remediate that heightened risk by following marijuana etiquette.