Wicked problems are open-ended, highly interdependent issues that cross agency, stakeholder, jurisdictional, and geopolitical boundaries. In response, there has been advocacy for interagency working. However, this confounds conventional approaches to government because policies and budgets tend to be aligned within organizational boundaries and not across them, making it difficult to bring the appropriate talent, knowledge and assets into an interagency approach to tackle the interdependencies of whatever wicked problem is at hand. In addition, the purposes, perspectives and values of the various government agencies and other stakeholders can often be in conflict. This paper reports on research to develop and evaluate a systemic intervention approach involving the use of multiple methods underpinned by boundary critique to address a wicked problem. The major focus is how to create a common understanding of a wicked problem among multiple agencies using a participatory problem structuring method called ‘systemic perspective mapping’. The wicked problem we tackled was international organized drug crime and its intersection with local urban gang activity (using Chicago, USA, as a representative city). Perspectives on the problem were structured with participation from various local, regional and federal agencies involved in countering illegal drug trafficking. Our research found that the combined use of boundary critique and systemic perspective mapping was able to generate enough of a common understanding to provide a foundation for the design of an interagency organization using the viable system model (the latter is reported elsewhere in the literature).