Pierre Rosetti was born in Bucharest in August 1927, in a family of Romanian intellectuals, a historic family, among the significant in modern Romania. His father, Ion Rosetti (1893–1971), who attended high school and Law School in Paris, was a lawyer and professor at the University of Bucharest. In 1950 he was excluded from the University without any retirement provision because he had studied in an ideologically opposite country to communist Romania, namely France. Pierre Rosetti attended the Dimitrie Cantemir High School in the capital and entered the Faculty of Mines and Metallurgy at the Polytechnic School in Bucharest. At the time of the establishment of the communist regime in the country, in 1948, he was a student in the second year. Facing problems in college because of his "unhealthy origins," he decided to flee the country along with two colleagues by crossing the Danube to Yugoslavia. After almost a year in Yugoslav and Bulgarian prisons, he managed to reach France. There he continued his studies at the École Nationale Supérieur des Mines de Paris, specialising in engineering. He worked in the fields of mining, metallurgy (special steels, alloys), the textile industry, electricity, and electronics. In 1967–1968 he was naturalised as a French citizen.