This study aims to identify the indicators/indices for measuring current cities’ creative performance and the individual weight of each in that performance. To do so, a review and compilation of theoretical and empirical indices already developed was undertaken, showing culture, the creative economy, and a favourable environment as inseparable sub-dimensions of creativity. This compilation allowed the construction of a Composite Index for Creativity, using a quantitative methodology, which revealed 17 factors determining cities’ creative performance, for the evaluation of performance in the Portuguese context, which allows monitoring the degree of implementation of some of the targets of the 2020 Strategy. The results illustrate that Portugal follows the European tendency of including creativity in its strategies as an economic factor determining growth. With scientific rigour and quality, the weights of each sub-dimension studied in the Composite Index were determined, this being the study’s main contribution. Other implications for theory and practice and an agenda for future research are also presented.