In 1952, Pelli moved to the United States with his wife, Diana Balmori (1932–2016), and became a naturalized citizen in 1964.
After his graduation from the University of Illinois School of Architecture, Pelli worked for Eero Saarinen in Bloomfield Hills, Michigan, for ten years.
While with Eero, he worked on the TWA terminal at John F. Kennedy International Airport and the Morse and Stiles colleges at Yale University.

In 1964, he became director of design at Daniel, Mann, Johnson and Mendenhall in Los Angeles.
In 1965, Pelli designed the Sunset Mountain Park Urban Nucleus (an unbuilt project).
In 1968 Pelli became partner for design at Gruen Associates in Los Angeles.
In 1969, Pelli designed the COMSAT research and development laboratories in Clarksburg, Maryland.
Pelli designed his first landmark building with the Pacific Design Center in West Hollywood, California, which was completed 1975 and became known by the locals as the "Blue Whale".
The United States Embassy in Tokyo, Japan, was designed by Pelli in 1972 and completed in 1975.
While practicing in Los Angeles, Pelli taught in the architecture program at UCLA.
In 1952, Pelli moved to the United States with his wife, Diana Balmori (1932–2016), and became a naturalized citizen in 1964. After his graduation from the University of Illinois School of Architecture, Pelli worked for Eero Saarinen in Bloomfield Hills, Michigan, for ten years. While with Eero, he worked on the TWA terminal at John F. Kennedy International Airport and the Morse and Stiles colleges at Yale University.
In 1964, he became director of design at Daniel, Mann, Johnson and Mendenhall in Los Angeles. In 1965, Pelli designed the Sunset Mountain Park Urban Nucleus (an unbuilt project). In 1968 Pelli became partner for design at Gruen Associates in Los Angeles. In 1969, Pelli designed the COMSAT research and development laboratories in Clarksburg, Maryland. Pelli designed his first landmark building with the Pacific Design Center in West Hollywood, California, which was completed 1975 and became known by the locals as the "Blue Whale". The United States Embassy in Tokyo, Japan, was designed by Pelli in 1972 and completed in 1975. While practicing in Los Angeles, Pelli taught in the architecture program at UCLA.
César Pelli