In 2012 the Italian Parliament introduced into Italian law a special section in the Companies Register and a large number of financial incentives to create a favorable environment for the development of innovative start-ups (ISUPs). In this paper we compare ISUPs with other start-ups. In accordance with the eligibility criteria established by law, ISUPs show a striking capacity for innovation apparent in a higher incidence of intangible assets and the longer time it takes to begin selling their products, even when compared with other high-tech start-ups. ISUPs also report higher investment rates and stronger growth in sales and assets, while their financial structures are characterized by higher capitalization and greater availability of liquid assets. Based on propensity score matching, we also highlight some direct effects of the 2012 law on their financial structures, almost exclusively on ISUPs operating in the service sectors: their external funding, either debt or equity, increases more than for other similar firms; a stronger rise in investment rates is specifically associated with a larger upsurge in their capital.