Maria Luísa Costa Dias (1916–1975), was a Portuguese medical doctor and communist activist in opposition to the authoritarian Estado Novo government.

Maria Luísa Palhinha da Costa Dias was born in the city of Coimbra, on 15 October 1916, to a wealthy family.

[1][2] In 1947, Costa Dias moved to Mozambique, together with her future husband, Pedro dos Santos Soares, who at that time was a high school teacher.

Tales from concealment, a book that was published posthumously in 1982 about the lives of children in hiding and even of some inside Estado Novo prisons who were accompanying their mothers.

[1][2] On 3 December 1953, Costa Dias was arrested by the PIDE (International and State Defence Police) while staying at a secret location in Palmela.

She was released on health grounds on 18 December 1954, leaving the prison by ambulance, after a major campaign at national and international level.