This paper examines the determinants of neighborhood readiness to engage in collective action for substance abuse prevention. Factors investigated include community composition (characteristics such as SES, presence of children, racial composition), community context (drug problems and police resources), and community organization (formal neighborhood association functioning, informal neighboring, collective activities). Data were obtained from 188 community leaders who reported about their neighborhood, and census data were aggregated to the neighborhood level. Community composition and context factors had opposite effects on formal and informal neighborhood organization: SES was positively associated with informal neighboring and negatively associated with formal organization, while drug problem severity was negatively associated with informal neighboring and positively associated with formal organization. Yet, formal and informal organization were positively associated with one another, and both were positively associated with perceived readiness of the neighborhood to engage in additional drug prevention activities in the future.