[1] In 1957/58 he worked as an on-board physician in the Portuguese cod fishing fleet, an experience that inspired, among other writings, his sole prose effort.

Santareno left unpublished one of his most powerful plays, O Punho, which takes place during the post-revolutionary land reform (Reforma Agrária) in Alentejo.

The first plays were quite naturalist and colloquial but, from 1966 onwards (with O Judeu, about 18th century playwright António José da Silva, persecuted and killed by the Portuguese Inquisition), developed a more brechtian and interventionist tone.

In 1975 he collaborated, along with Ary dos Santos, in the text for the revue show (what is known, in Portuguese, as 'teatro de revista') P'ra Trás Mija a Burra.

Santareno, himself a "discreet homosexual",[2] often deals with homosexuality in his plays - it has a central place in works like O pecado de João Agonia,[3] or Vida Breve em Três Fotografias (about male prostitution) - along with multiple issues related to moral and social prejudice (adultery, virginity, the role of women in marriage, religious values, etc.).