Colombia approved a new political constitution in 1991 and undertook the opening of the economy and institutional reform, including legislative efforts to combat corruption, during the first years of the decade. Drug trafficking in Colombia has left a mark on the main cultural heritage of the past 20 years, affecting politics, both public and private administration, and the general and daily lives of citizens. The Colombian state is rapidly losing its legitimacy. Corruption in the political sphere, reinforced by drug trafficking and its particular culture, is the main cause of the Colombian Congress's discredit. The paper examines the contradiction between Colombia's efforts in fighting corruption through strengthening the laws and the lack of results. It also describes the Congress's legitimacy crisis and some of the challenges facing the Congress as it attempts to combat corruption. The paper reviews institutions and legal instruments against corruption, some deceiving indicators, building citizens' confidence and changing cultural parameters. Notes