This article focuses on the determinants of firm's growth in Brazil. In particular it investigates the individual characteristics of firm that determine its growth; how institutional development affects firm's performance, and how institutional development differently affects small and large firms. We find that, consistently with the learning models, growth is decreasing on age and negatively correlated to size. As expected, firms that belong to an economic group, export and maintain operations abroad grow faster. Growth is negatively correlated to profitability. Furthermore, we observe that shortcomings in institutional development, when measured in terms of corruption, inefficiency of the judicial system and lack of financial development, have a negative impact on firms' growth. This negative impact of corruption and inefficiency of the judicial system is stronger for smaller firms. Large firms benefit the most with financial development. Overall our results indicate that improvement in institutions can be an important mechanism to promote growth. Furthermore, institutional underdevelopment has the perverse effect of promoting concentration.