In the last twenty years, the Brazilian Financial System has suffered deep political and economic transformations. In the 1980s, under the huge inflation phenomenon impact, it experienced an expansion based on float gains, which were decreased by the implementation of the Real Economic Stabilization Plan, in 1994. In this new scenario, the financial institutions were forced to incur more credit, market and operational risks. After an initial adjustment period, described by a variety of liquidations, mergers and acquisitions, jointly with increasing nonregulation of the financial market, the system faced a new level of competition and risk by the end of 1999. The purpose of this work was to evaluate and quantify the contribution of various components of general risk and operational risk, in particular, in the development of the financial system during the period of 2000/2005. The major conclusions of the developed model were the following: (a) the classic components of the risk (market, credit and operational) had a relevant impact in the performance of the system; (b) the operational component presented hybrid, occurring with incidental and continuing contributions; (c) the leverage and the concentration level were not significant in the formation of system risk; (d) the role of the Central Bank through its surveillance departments, was relevant and effective in the minimization of system risk.