In 1997, he began working on the series Stargate SG-1, serving as Producer, Writer, Director, and creative consultant. He has appeared, normally as an extra, in every episode of the series he has directed. He went on to work as executive Producer, Director and Writer for the Stargate SG-1 spin-off Stargate Atlantis, and directed eight episodes of the spin-off Stargate Universe. His father, Dom DeLuise, made a guest appearance in the Stargate SG-1 episode "Urgo", which Peter directed. Peter also made a cameo in the episode as the "Urgo" character transformed to be a young man in a United States Air Force uniform.