Pierre Guariche attended the ENSAD (École Nationale Supérieure des Arts Décoratifs de Paris) where he studied under René Gabriel. He went on to work with Marcel Gascoin and became a member of the UAM. In 1948 he began showing his work at the Salon des Arts Ménagers and thereafter designing for Galerie Mai. From 1954-1957, Guariche developed the Atelier des Recherches Plastiques (ARP) with Joseph André Motte and Michel Mortier while simultaneously collaborating with highly important design firms like Airborne, Meubles TV, Huchers-Minvielle, Disderot, and Steiner.
In the late 1950s Guariche became head of the design studio of the Belgian company Meurop. There he created very elegant furniture for very low budgets. Perhaps best known for the lighting he designed for Disderot in the 1950s, Guariche was also a prolific and innovative chair designer.
At the height of his career, Guariche worked mostly as an architect, designing many private residences as well as commercial and public spaces, including several ski stations. Guariche saw himself as an architect first. His approach to both contemporary furniture and architecture is primarily motivated by emphasis on form and volume. Overall, his designs reflect a commitment to simplicity and to creating furniture in series that can be industrially produced.
In 1965, Guariche received the René Gabriel prize.