This dissertation analyzes the effects of inflation on the expansion of the financial system. To this end, Brazil provides a singular opportunity for research as the country experienced inflation of more than 1,000% per year for many years followed by an abrupt drop. Slightly more than a year after implementation of a successful stabilization plan it was close to 10%. The main result is when inflation is high, banks expand their branch network, more interested as they are in capturing funds as opposed to granting credit. On the other hand, when inflation is under control, banks begin to focus more on credit. The data also suggest that there was a change in the growth pattern of financial variables (branch, credit, and CD issuing) as related to characteristics of the municipalities such as market size, geographical location, level of development, and infrastructure. This evidence reinforces the premise that the end of inflation prompted structural change in the Brazilian financial system. The dissertation emphasizes the importance of the institutional environment for the development of the credit market.