He was born into a family with a political background in the Christian Democratic People's Party. After he graduated from the faculty of Law from the University of Zurich, he worked as an independent lawyer in Brig. Since his early years he was interested in leftwing politics and was one of the founders the political magazine Red Anneliese. In 1971 Peter Bodenmann co-founded the Critical Upper Valais movement as he was 24 years old, he became a local councilor of Brig-Glis. In 1982 he opened a law office in Brig and in the same year the movement Critical Upper Valais merged with the SP Upper Valais.
After leaving politics in 1999, he became the owner of a Hotel in Brig. He has also been writing columns on political and economic topics in the Weltwoche and has earned himself the nickname Oracle of Brig. Through his prominence as a former SP president and a political columnist, he maintained quite some influence in the politics of the SP. It was assumed that his political entourage supported Ursula Kochs reassignment of the presidency of the SP.