The aim of this paper is to quantify the productive diversity of the manufacturing industry in the provinces of Argentina, to analyse trends in productive diversity between 1996 and 2012, and to identify the main related economic factors. A diversity index is calculated based on official data on total registered wage employment from the Dynamic Employment Analysis Database (BADE). An analysis is then performed of trends in diversity in the different provinces over the period. Lastly, an econometric panel data model is estimated to identify the main related economic factors. The industrial diversity of the provinces is negatively associated with withdrawal of firms and positively associated with level of development, region size, higher levels of urbanization and greater territorial capabilities. The results of this study can be used to design policies to promote regional diversity.