Pascal was born in Santiago, Chile, to a child psychologist mother and a father, Jose Balmaceda, who is a fertility doctor. Pascal's parents were Allende supporters, and were involved in the opposition movement against the US-backed military dictatorship of Augusto Pinochet in Chile around the time of his birth. Because of this, soon after his birth, his family was granted political asylum in Denmark. He was raised in Orange County, California and San Antonio, Texas. He has Spanish roots from a Basque grandfather and Majorcan grandmother. Pascal was involved in competitive swimming during his early years, taking part in the state championships in Texas at the age of eleven, but immediately stopped competitive swimming after getting into drama class. He studied acting at the Orange County School of the Arts and New York University's Tisch School of the Arts and has been living in New York City for over 20 years. Pedro's younger brother Lucas Balmaceda is an actor in Chile.