He served as Federal Minister of Finance of Germany in the Cabinet of Chancellor Helmut Kohl from 1989 to 1998, and as Chairman of the Christian Social Union in Bavaria from 1988[1] to 1999.

He not only had to impose enormous new taxes on the German public, but he also had to keep the country's budget deficit from ballooning while Germany was spending $150 billion a year to rebuild the east.

[8] In July 1990, Waigel joined Kohl and Foreign Minister Hans-Dietrich Genscher on a trip to Moscow to meet President Mikhail S. Gorbachev, where they worked to convince the Soviet leader to drop his remaining objections to German unification within NATO.

[14] In the national debate on whether the federal government should remain in Bonn or move to Berlin, Waigel argued that Germany had assumed enough major financial obligations over the preceding years and could not afford to build a new capital.

[15] In early 1996, Waigel and his French counterpart Jean Arthuis launched a French-German economic stimulus package aimed at encouraging spending, increasing growth, cutting taxes on business and reducing unemployment.

[16] In the subsequent years, however, both CDU and CSU favored increasing taxes, fearing the consequences of further budgetary cuts; by 1997, the government was already in danger of breaking a Constitutional Court ruling that spending on public investment must exceed the budget deficit.

[18] Soon after taking office, Waigel negotiated with his counterparts of the G7 on the difficult question of rankings in the voting hierarchy of the International Monetary Fund (IMF).

[21] On initiative of Waigel, the Bundestag establied the German Federal Environmental Foundation (DBU) in 1990, using the amount of €1.3 billion from privatizing the former steel group Salzgitter AG.

[25][26] Throughout the 1990s, Waigel was seeking to assure a skeptical German public as well as small companies and banks that the new currency would be as stable as the Deutsche Mark, which had become a symbol of Germany's economic hegemony in Europe at the time.

He later overruled the French government with his proposal; France had favored want the name ECU, the European Currency Unit which was used in many accounts and the issuance of some debt at the time.

[30] In 1998, he joined fellow finance ministers Gerrit Zalm of the Netherlands, Rudolf Edlinger of Austria and Erik Åsbrink of Sweden urging President of the European Commission Jacques Santer to cap the proportion of a country's income which goes to the EU as part of his Agenda 2000 spending review.

[31] After his failed attempt to pressure Bundesbank president Hans Tietmeyer into a quick revaluation of the country's gold reserves in order to bring Germany's budget deficit into line with the criteria for the single currency, Waigel had to confront a parliamentary motion against him on 4 June 1997.

[36] In 2011, a commentator seeing Germany forced perhaps to choose between monetary stability, on the one hand, and the EMU, recalled by way of contrast Waigel's statement at the founding, "We are bringing the D-Mark into Europe.

[51] In 2008, following revelations about violations of the Foreign Corrupt Practices Act, the German industrial conglomerate Siemens agreed to install Waigel as an outside corporate monitor for four years.

In 2012, Waigel joined a newly established external advisory panel under the leadership of Jürgen Hambrecht at Deutsche Bank, which was to review compensation and governance at the company.

[63][64] In 2021, he was appointed to co-chair – alongside Brigitte Zypries – an independent expert commission established by audit firm Ernst & Young to assess its involvement in the Wirecard scandal.