Though the link between trust and transparency is a central concern of social science, the relationship between the two concepts has remained a `black box'. Many empirical studies concentrate solely on verifying whether transparency impacts trust and do not elaborate on the mechanisms that facilitate this relationship. Trust and transparency need to be qualified to be understood and captured in a meaningful sense by empirical research. Hence, the article proposes an interpretative matrix for exploring relationships between types of trust and transparency. It presents a framework of analysis that is sufficiently precise to make sense of complex interactions in six European regions in three European states (the UK, Germany, and France) and sufficiently generic to have a heuristic value as a tool for comparative study. It also contributes to broader discussions of the role of trust and transparency as factors of public management. The framework might equally be applied to evaluating trust and transparency as modes of public action in fields such as health or the environment.