She began working with ceramics in the late 1960s, learning the technique of floor-standing kilns in Ribolhos in the Viseu District from Maestro Albino, considered the last traditional potter in Portugal.

[3][4] She has exhibited regularly since 1982 and in 2017 she held a retrospective exhibition:, Maria José Oliveira: 40 anos de Trabalho (Maria José Oliveira: 40 Years of Work) at the Sociedade Nacional de Belas Artes [pt] in Lisbon, establishing her work as some of the most important in Portuguese contemporary art.

[3] Oliveira uses common or garden raw materials of no intrinsic value to create works of art, including her jewellery designs, which eschew the use of valuable metals or stones, and have been called "anti-bourgeois".

[5] Most of her works are composed of natural and organic materials, some of which are degradable, such as plant residues, dried leaves, eggs, vegetable resin, bread dough, baker's oven ash, and handmade paper.

[1][6] She has been called "an artist of the colours of the earth, of golden yellows, of the infinity of shades of grey, of lime washes, of porcelain whites, of the tones and timbres of graphite and charcoal" by the art historian Raquel Henriques da Silva.