As Europe is currently characterized by huge disparities in the economic performance of “old” and “new” states, we investigate whether this is the result of local agglomeration—specialization and diversity—externalities. Our spatial econometric analysis focuses on total factor productivity dynamics over the period 1996–2007 for 13 industries located in 276 European regions. Consistently with the “nursery cities” theory, we find that diversity exerts a positive effect in the knowledge-intensive services of the “old” Europe urban areas, while specialization is still effective in the “new” Europe low-tech manufacturing. Human and technological capital has also a positive impact.