In this paper we design and build a composite indicator to measure the macroeconomic, social and institutional dimensions of countries, ISEPI. The index allows not only comparing the relative situation of countries, but also its time evolution. In order to illustrate the usefulness of the index, we analyse the effects of the European Neighbourhood Policy in EU-Neighbouring Countries during the last decade. The obtained results show that ENP has had different effects according to the considered dimensions and that the evolution of neighbouring countries is quite heterogeneous taking into account their recent institutional and economic performance. From a policy perspective, these results reinforce the validity of the bilateral action plans that have characterized ENP recognising the different starting point and particular characteristics of each neighbouring country.