Isidre (or Isidro) MonÚs was born in Barcelona in 1947. When he was fifteen, he started to work on advertising as an apprentice. He was a drawer at several advertising agencies, until he became an illustrator at the age of 20. He illustrated children's books, covers and trading cards. MonÚs felt professionally attracted to comics when he discovered the work of such innovative artists as Dino Battaglia. He entered this field by means of the international agency Selecciones Ilustradas in the early 1970s. His works appeared in US horror magazines Creepy, Eerie and Vampirella, where he collaborated with such script-writers as Doug Moench, Budd Lewis and Nicola Cuti. With Gerry Boudreau he did the series 'Doctor Archeaus' in Eerie.
In 1976 Isidre MonÚs left Warren temporarily and he drew strips for Scottish publisher DC Thomson's magazines Commando and Bullet. By the early 1980s he was one of the artists for this publisher's SF strip 'Starhawk'. MonÚs drew his last comics during this decade, alternating them with his illustration work. He went on working as an illustrator ever since.
The few comics that MonÚs did exclusively for the Spanish market include works for such different magazines as Mata Ratos and Cavall Fort, a short story for Rambla and another one called 'El Fracaso' for the Spanish version of SF magazine 1984.