On the eve of the Brexit process, in the context of a rising Euroscepticism that fuels the modest confidence of European citizens in their national and European institutions, the article assesses the efficiency and effectiveness of the European Parliament within the framework of the ordinary legislative procedure (co-decision). After defining and formulating the main indicators, the paper analyses the micro- and macro-performance of the European Parliament within the decision-making process from a quantitative-qualitative and a qualitative-quantitative perspective, highlighting the relativizing factors and the responsiveness of the European decision-making process to the Europeans’ needs.