The role of Development Banks has been widely discussed for decades, whose presence and performance have defenders and critics. Since its founding in 1952, the National Bank for Economic and Social Development (BNDES) has been in the center of these discussions as it is among the 4 largest development banks in the world, playing an important role in the Brazilian economy. This research focused on companies listed on the São Paulo Stock Exchange (Bovespa) from 2002 to 2014, with emphasis on the relationship between financial restraint and BNDES loan contracting. For this, the Cash Flow Sensitivity model was used through regression by means of fixed, random effects and grouped data in an unbalanced static data panel. Another aspect of this study was to verify the differences between the companies that hired and did not borrow from the BNDES in periods related to the 2008 global financial crisis, whose analysis was developed by the Difference-inDifferences test. The results showed that, in the general sample, there was a financial constraint in both groups of companies, and the restriction was greater in the companies that contracted BNDES loans. In this group, companies that borrowed directly from the BNDES (direct support or non-automatic mode) had greater financial constraints. The financial institutions that operated with the BNDES (Indirect support form or Automatic mode) had the lowest financial restrictions. In relation to the financial crisis, the test showed that the level of investment and the financial constraint of the treatment group had significant differences in the pre-crisis and crisis periods, which may indicate an influence of the BNDES in mitigating the effects of the crisis. This study concludes that the companies that contracted BNDES loans have greater financial constraints than those that did not take out a loan. In addition, the study points out that in the financial crisis of 2008, the presence of BNDES financial resources, in these companies, contributed to reduce the financial constraint, while the companies that did not contract loans were more restricted. These findings confirm the role of the development bank working in companies that showed greater need for capital, as well as reducing financial constraint in times of crisis.