 His first formal exhibition took place in September 1933 at the Libreria Walton, a centre of cultural events.This event was sponsored and introduced by the poet Vicente Huidobro, with whom Carlos Sotomayor shared a close friendship.In 1934 Sotomayor joined the Grupo Decembrista, together with María Valencia, Gabriela Rivanedeira, Jaime Dvar and Waldo Parraguez.