Although industry clusters are major targets of regional economic development in less developed regions as well, we still need a deeper understanding of how the spatial clustering of firms generates dynamics in lagging regions. These latter environments may differ from the typical cluster policy examples that are usually specialised global centres of dynamically growing industries. Using census-type data of Hungarian firms, we test the effect of major cluster indicators — regional specialisation and spatial concentration of industries — and the impact of FDI on regional productivity and employment growth in Hungary. Our results suggest that regional specialisation does not affect regional growth, while the spatial concentration of industries is found to influence productivity and employment growth with an overwhelmingly negative effect. Furthermore, regional employment growth is associated negatively with the initial level of regional specialisation. Results suggest that Hungary has evolved into a dual economy in which previously specialised regions and geographically concentrated industries have lost their pace, while the main factor that favoured regional economic growth was the presence of large foreign companies. Therefore, economic policies fostering regional specialisation and the spatial concentration of industries — such as cluster policy — may have minor effects unless the interaction of foreign-owned and domestic companies is encouraged.