Ms Polfer was born in Luxembourg on 22 November 1952.
In 1972 Ms Polfer completed her secondary education at the Lycée Robert Schuman. Four years later she received a Master’s degree in law from Grenoble University. Since 1977 she has been a member of the Luxembourg Bar. That year she obtained a postgraduate diploma on European integration from the Centre universitaire de Recherches internationales et européennes in Grenoble.
She embarked on her political career in 1979, when she was elected to the Luxembourg Parliament for the first time. She was re-elected in 1984, 1989 and 1994.
As an MP she was a member of the Bureau of the Chamber of Deputies and of the Municipal Affairs, Housing and Town Planning Committee, the Special Committee on Equal Opportunities for Women and Men and the Civil Service Committee.
In 1982 she became Mayor of the City of Luxembourg as a result of the October 1981 local elections. She was re-elected in 1987 and 1993. She was a member of the European Parliament from 1985 to 1989 and 1990 to 1994. In 1994 she became leader of the Democratic Party.
She has been a member of the Bureau of the AIMF (Association internationale des Maires et Responsables des Villes et Métropoles partiellement ou entièrement francophones). Since 1980 she has been President of the Racing de Luxembourg basketball club.
As an outgoing MP and a Democratic Party candidate in the general and European elections of 13 June 1999, she was re-elected in the central constituency on behalf of her party, which won seven seats in that constituency.
After the 1999 general election she was appointed Deputy Prime Minister, Minister for Foreign affairs and Foreign Trade and Minister for the Civil Service and Administrative Reform.