From 1955 to 1959, Piero Bellugi was the conductor of the Oakland Symphony Orchestra, followed by the same position at Oregon Symphony Orchestra in 1959–61. He debuted at Teatro alla Scala, Milano in 1960 with Georg Friedrich Händel's opera Serse and became a guest conductor at La Scala the next year. In 1967, Bellugi started working as a permanent conductor of the Orchestra Sinfonica Di Torino Della RAI, and also acted in the same role at the Orchestra Giovanile Italiana.
As a guest conductor, Piero Bellugi had appeared with Orchestra Del Teatro Dell'Opera Di Roma, Orchestre National De L'Opéra De Paris, Orchestra dell'Accademia Nazionale di Santa Cecilia, The Lyric Opera Of Chicago Orchestra, San Francisco Opera Orchestra, and many other ensembles. Throughout his career, Bellugi conducted world premieres of several important pieces, including Darius Milhaud's Symphony No. 10 in 1961 and Settimo Concerto by Goffredo Petrassi in 1965.
He gave workshops at several prestigious institutions in Europe and the United States, including the University of California, Berkeley, New England Conservatory Of Music, and the Accademia Musicale Chigiana. In 1996, Piero started teaching at the Luigi Cherubini Conservatory. His son, David Bellugi, (b. 1954) is a recorder virtuoso.