Bangemann was a member of the European Parliament from 1973 to 1984.
Bangemann was the German Federal Minister of Economics from 1984 to 1988.
In 1989, Bangemann joined the European Commission. He was Commissioner for the internal market and industrial affairs in the Delors Commission from 1989 to 1995. He was then Commissioner for Industrial affairs, Information & Telecommunications Technologies in the Santer Commission from 1995 to 1999.
Since 1 July 2000, Bangemann has been an executive of the Spanish telecommunication company Telefonica. His move to Telefonica was the topic of much controversy and a lawsuit by the EU in 1999, because of possible conflicts of interest with his previous post as the telecommunications commissioner. The lawsuit was dropped when Bangemann promised not to start work for a third party before 2001. Since July 2001, he has been a board member of Hunzinger Information AG.