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. This group of neocubist artists was led by Vicente Huidobro. Two years later, Carlos Sotomayor married Franka Serka Jurac, fellow student at the Fine Arts College. In 1938 he joined the Grupo Rectángulo de Arte Moderno, encouraged by the artist Vergara Grez. He exhibited at the Alianza de Intelectuales de Chile together with María Valencia, Waldo Parraguez and Haroldo Donoso. In August 1944 he exhibited 20 paintings at the Sala del Ministerio de Educación. In the catalogue there were articles and poems by the poets
Eduardo Anguita and Julio Molina. The critic Antonio Romera wrote a very complimentary review in the press. In 1946 Sotomayor exhibited several oil paintings and drawings at the Sala del Ministerio de Educacion. The writer
Andres Sabella wrote an article about it. In December 1952 Sotomayor exhibited at the Sala Pro Arte and in 1953 he took part in the Primer Salon de Primavera de la Casa de la Cultura de Nunoa, together with 50 other artists:
José Balmes, Sergio Montecinos, Raul Santelices and José Venturelli among them. In 1955 he started working at the Chilean Railway Company (
EFE) as a draughtsman in the Department of Vias & Obras. In 1960 Sotomayor took part in
La Segunda Feria de Artes Plasticas (Parque Forestal) organised by the
Museo de Arte Contemporáneo. Sotomayor won second prize. Sotomayor exhibited his works at the Exposicion de Pintura Chilena Nueva in March 1962, organised and sponsored by Empresa Esso Oil Co.
Nemesio Antúnez and José Balmes also participated. In November 1966 Sotomayor exhibited his oil paintings at the Sala del Instituto de Artes Plasticas de la Universidad de Chile. His last exhibition while he was alive, took place in 1979 at the Galeria Eco, where there were 30 of his paintings, among them:
The painter and his models,
Rape 1 and
Landscapes of Cartagena. The art critic José María Palacios praised Sotomayor’s works in the press. In 1973 Sotomayor retired from the railway company and devoted himself entirely to his paintings until his death. In 1984 he travelled to
Europe where he visited museums of modern art in
Paris,
London,
Birmingham and
Rome. In 1988 he suffered a
heart attack from which he did not recover and died on 17 April. In the year 2004, an exhibition of his paintings was organized at the Cultural Corporation of
Las Condes, so called "Carlos Sotomayor: A modern classic" ==A Unique Figure in Chilean Painting (by
J. Palacios)==