[1][2] Houaiss began his career in Rio de Janeiro as a professor of the Portuguese language, of which he eventually became a recognized authority.

[1] He left teaching in 1945 for the diplomatic service and served the Brazilian government as such until the 1964 military coup, when he was forced to retire with loss of political rights.

[3] After leaving the diplomatic career he worked briefly as editor of the Brazilian newspaper Correio da Manhã (1964 to 1965).

[3] He was also one of the chief proponents of the international unification for the orthography of Portuguese, a project that he had joined in 1985,[3] and led to the 1990 spelling reform treaty, which he too did not live to see implemented.

He is best known for his 1966 translation of James Joyce's Ulysses,[5][6] and for supervising with Mauro de Salles Villar the creation of the Dicionário Houaiss da Língua Portuguesa,[7][8] one of the major reference dictionaries for the Portuguese language[according to whom?].