In this work, a comparison between start-up companies’ performance is made based on the way they use the Portuguese R&D tax credit program. From the analysis of the results, it is possible to verify that companies that benefit from this program have a distinct behavior from those that do not, either in what regards financial performance, the weight of the intangible assets in the company or in what regards the quality and value added of the jobs created. It is also possible to find that beneficiary companies mix the tax credits with the use of European, national and regional grants, thus mixing the funding available to support their Research, Development and Innovation activities.