Between the late 1980s and the mid-1990s, the perception of many contributors to régulation theory and evolutionary economics was that, because of a certain proximity in the issues and presuppositions of each approach, it might be fruitful for both to engage in a scientific dialogue that could lead to what Chris Freeman imagined might be an original synthesis. More than three decades later, it has to be said that the synthesis has not taken place and that the dialogue has lost much of its intensity. This article analyses the reasons that have led the two approaches to move further apart rather than closer together, by examining how régulation theory has integrated the problems of technology and dealt with agents’ diversity at the micro level, and how evolutionary theory has tackled the issue of macro-level institutions. It emerges that structural reasons relating to each ofthe approaches prevent genuine convergence, but that this does not represent a problem for which a solution should necessarily be sought.