Azevedo was born in São Luís, to David Gonçalves de Azevedo (the Portuguese vice-consul in Brazil) and Emília Amália Pinto de Magalhães. He was the younger brother of the famous playwright Artur Azevedo.

As a child, Aluísio would work as a traveling salesman. Since then, he loved painting and drawing, and would move to Rio de Janeiro in 1876 (where his brother Artur was living already), to study at the Escola Nacional de Belas Artes. After graduating, he drew caricatures for journal such as O Fígaro, O Mequetrefe, Zig-Zag and A Semana Ilustrada.

His father's death, in 1878, made him return to São Luís, in order to take care of his family. He then initiated his writer career, publishing in 1880 a typical Romantic novel, Uma Lágrima de Mulher. He helps on the creation of an anticlerical journal named O Pensador, where he wrote Abolitionist articles. In 1881 he publishes the first Brazilian Naturalist novel ever: O Mulato, that deals with the racism. Consolidating his career as a writer, he could return to Rio.

He would write endlessly during the period of 1882-1895. Dating from this period are his also famous novels Casa de Pensão (1884) and O Cortiço (1890), and many other works written in partnership with his brother, or with Émile Rouède.

In 1895 he became a diplomat. He served as a minister in Spain, Japan, England, Italy and Argentina, where he died.

Novels

• Uma Lágrima de Mulher (1880)
• O Mulato (1881)
• Mistérios da Tijuca, ou Girândola de Amores (1882)
• Memórias de um Condenado, ou A Condessa Vésper (1882)
• Casa de Pensão (1884)
• Filomena Borges (1884)
• O Homem (1887)
• O Cortiço (1890)
• O Coruja (1890)
• A Mortalha de Alzira (1894)
• O Livro de uma Sogra (1895)

Theatre plays

• Os Doidos (1879)
• Flor-de-lis (1882)
• Casa de Orates (1882)
• O Caboclo (1886)
• Fritzmack (1889 ... in partnership with Artur Azevedo)
• A República (1890)
• O Adultério (1891)
• Em Flagrante (1891)

Miscellaneous

• O Japão (chronicles ... 1894)
• Demônios (short stories ... 1895)