The main aim of the paper is an ex-post assessment of the 2004-2006 European cohesion policy programs in Poland. The authors analyze the potential impact of structural interventions on production and employment in Polish regions at the NUTS2 level. Instead of the typical demand and short-term approach dominant in the majority of previous studies, the authors rely on a supply approach based on an augmented regional production function. Moreover, the authors take into account regional heterogeneity by distinguishing three different groups of regions: high-income regions, middle-income regions and low-income regions. The authors find that the EU’s cohesion policy in Poland is effective in terms of both regional output and employment. This means that in the case of Polish regions, structural funds and the Cohesion Fund play an important role in regional economic growth and in income convergence with the “old” EU15 countries. Yet, the article also shows that the real impact of structural interventions on regional employment is much lower than suggested by previous simulations based on Computable General Equilibrium (CGE) models, the authors say.