To sustain growth, many European countries have been rethinking their National Innovation Systems for decades. As the time has come for the assessment of these policies, more and more evidence is brought regarding the low level of gazelles created. The objective of this paper is to explore means of increasing the level of gazelles among New Technology-Based Firms (NTBFs) that graduated from the French public incubators. In other words, the challenge is to identify the main barriers to growth for such firms and then to suggest relevant recommendations to overcome these barriers. In fact, a recent survey conducted in June 2007 showed that from 1999 to 2006, 901 start-ups graduated from the public incubators out of 1050 projects. While their average number of employees is 5, only 4.2% of them have revenue of more than 1 million Euros.