1950
July – the Oiticica family returns to Rio de Janeiro.

1952
Hélio writes and translates plays which he stages at home with his brothers and cousins under the direction of their aunt, actress Sônia Oiticica (1921-2007).

1953
December / January – The Oiticica family travels to visit the Second Biennial, the II Bienal do Museu de Arte Moderna de São Paulo, which includes special galleries dedicated to Paul Klee (1879-1940), Alexander Calder (1898-1976), Piet Mondrian (1872-1944), and Pablo Picasso (1881-1973).

1954
Hélio Oiticica and his brother César Oiticica begin to study painting with Ivan Serpa (1923-1973) at the Museu de Arte Moderna do Rio de Janeiro (MAM-RJ).

1955
Hélio Oiticica comes contact with the Grupo Frente and participates in the group's second exhibition at Rio de Janeiro's Museu de Arte Moderna. It was probably during this period that he met the artist Lygia Clark (1920-1988) and art critics Mário Pedrosa (1900-1981) e Ferreira Gullar (1930).

Starts to paint gouaches on cardboard.

Show: July 14 – second show of the Rio de Janeiro group, II Exposição do Grupo Frente, at MAM-RJ.

1956
Continues to produce gouaches on cardboard. In December, he begins to work on a series of twenty-seven pieces in this medium, called Secos.

Shows: “Pintura Brasileña Contemporánea” [Contemporary Brazilian Painting], Instituto de Cultura Uruguayo Brasileño (ICUB), Montevideo; March 17 – III Exposição do Grupo Frente [Third exhibition of Grupo Frente], Itatiaia Country Clube, Resende, State of Rio de Janeiro; April 12 – “Exposição Nacional de Arte Concreta” [National Exhibition of Concrete Art], Museu de Arte Moderna de São Paulo (MAM-SP); June 23 – IV Exposição do Grupo Frente, Volta Redonda, State of Rio de Janeiro.

1957
Along with Ivan Serpa (1923-1973), Aluísio Carvão (1920-2001), César Oiticica (1939), Alberto Pinedo and Henry Dobbin, he participates in the organization of the Instituto de Arte Infantil [Children’s Art Institute], a primary school that emphasizes the teaching of visual arts. Operational until 1959, the school was located in a house at number 39, Rua Lins de Vasconcelos.

Hélio and his brother César attend the Noite de Arte Concreta [Concrete Art Night] at the União Nacional dos Estudantes (UNE), an event that takes place in Rio de Janeiro concurrently with the I Exposição Nacional de Arte Concreta, at the Ministério da Educação facilities. São Paulo Concrete poet Décio Pignatari (1927) presents a lecture that provokes intense controversy in the audience divided between radicals – the brothers Haroldo (1923-2003) and Augusto de Campos (1931), and Ferreira Gullar, among others, and champions of more traditional poetry, such as Olegário Mariano (1889-1958) and Ledo Ivo (1924).

June 30 – José Oiticica dies.

The Secos series evolve into another group of gouaches on cardboard, which Oiticica would refer to (in a 1972 text) as Metaesquemas.

Shows: February – I Exposição Nacional de Arte Concreta, Museu de Arte Moderna do Rio de Janeiro; September – “Arte Moderno en Brasil” [Modern Art in Brazil], Museo Nacional de Bellas Artes, Buenos Aires; September – IV Bienal do Museu de Arte Moderna de São Paulo.

1958
The year signals the last of the Metaesquemas and the beginning of the Série Branca [White Series].

1959
Lygia Clark and Ferreira Gullar invite Hélio Oiticica to join the Grupo Neoconcreto in Rio de Janeiro.

The Série Branca [White Series] evolves from painting on cardboard to oil paintings on canvas and wood. Paints several monochromes, including triangular paintings in white and red, as well as the Invenções [Inventions] series. Begins the Bilaterais [Bilaterals] series.

Shows: September /December: V Bienal do Museu de Arte Moderna de São Paulo;
November 11 – “Exposição Neoconcreta,” held at Belvedere, Salvador, State of Bahia.

Writings: December, 1959/May, 1964 – Diary 59/64, doc nº 0182 AHO/PHO. Diary 59/63, doc nº0207/59 AHO/PHO.