Pietro Maria Castiglioni, known as Piero, was born in Lierna (Lecco) in 1944. After graduating in architecture in 1970, he worked with his father Livio in Via Presolana from 1973-1979, mainly specializing in lighting design. In 1968 and 1973 he was asked to work for both 14th and 15th "Triennale di Milano". In 1972 he carried out design work with Ugo La Pietra for the exhibition entitled "Italy: the new domestic landscape" at the Museum of Modern Art in New York.
Along with his father, he created several lighting designs for public or private art galleries, temporary exhibitions, show rooms, offices, hotels and houses both in Italy and in foreign countries. They often designed special execution lights made by craftsmen, eventually resulting in the creation of the "Scintilla" system, manufactured by FontanaArte. Piero continued working on interior and outdoor lighting design following his fathers death in 1979.