Rognoni began his political career in local government, serving as a city councillor in Pavia from 1960 to 1964, and from 1964 to 1967 as deputy mayor and as councillor for town planning. He then entered national politics, and was elected member of the Chamber of Deputies for seven consecutive terms (1968–1994).
Rognoni was Minister of the Interior from 1978 to 1983, of Justice (1986–1987) and Minister of Defence (1990–1992): he faced the terrorism and he solved the kidnapping of James Lee Dozier by the hand of Brgate Rosse. He was criticized by the Italian Communist Party while Minister of the Interior for failing to protect General Carlo Alberto Dalla Chiesa, who was killed on the same day in which he asked Rognoni to meet him.
From 2002 until he retired in 2006 he was vice-president of the High Council of the Judiciary (Consiglio Superiore della Magistratura).
Rognoni died in Pavia on 20 September 2022, at the age of 98.[1]