The paper discusses Italian and international advances in industrial district studies using two explanatory tools. First, it distinguishes between ‘the’ industrial district as a set of models of industrial organization and local development and industrial ‘districts’ as empirical cases with close relations with the models. Second, it uses a historical frame to delineate three waves of industrialization in which industrial districts have performed a prominent role. Recent studies are classified according to their interpretations of these three waves. Reflection on the strengths and weaknesses of ‘the’ industrial district as an useful interpretative tool is a linking theme in the paper. Keywords: industrial district; clusters; local and regional industrialization and development. JEL-classification codes: L60, 014, R30, R58.