He was born in San Piero Patti, Sicily. His family emigrated to the United States in 1920 and settled in Santa Rosa, California. He started his musical career playing the baritone, like his father, but he quickly branched out into other instruments, notably the French horn and the piano. He received a bachelor's degree from San Francisco State College, and then studied composition with Darius Milhaud at Mills College in Oakland, California.
After WWII Rugolo went to work for Stan Kenton who headed one of the most progressive big bands of the time. Rugolo provided arrangements and original compositions that drew on his knowledge of 20th century music, sometimes blurring the boundaries between the ballroom and the concert hall.
While Rugolo continued to work occasionally with Kenton in the 1950s, he spent more time creating arrangements for pop vocalists, including June Christy, Peggy Lee and the Four Freshmen. During this period he also worked for a while on musicals at MGM, and served as an A&R director for Mercury Records in the late 1950s. Among his many albums were Adventures In Rhythm, Introducing Pete Rugolo, Rugolomania, Reeds In Hi-Fi and Music For Hi-Fi Bugs.