The decisive role of the knowledge-based economy, and the importance of the ventures fostering the use of innovation and incorporating knowledge, high technology and creativity are nowadays worldwide recognised, even more so considering that the EU is in a permanent search for innovation as a source of and for competitiveness. Knowledge Intensive Business Services (KIBS) are expected to play a key role in the knowledge-based economy as a source of innovation and knowledge in production, dynamic hubs in knowledge-related networks, or intermediaries of innovation between the manufacturing sector and suppliers, partners and final consumers. Within this context, in the present paper we aim to investigate the complex relation between the knowledge intensive business services (KIBS) and the imperative of fostering the economic activity, both of the entrepreneurial dynamics and their macroeconomic effects. The analysis, performed at EU level, leads to interesting results, revealing a complex but contradictory relation between KIBS and economic activity, which is measured by the following main indicators: entrepreneurial density and macroeconomic dynamics.