She took a degree in Hispanic Philology, Galician-Portuguese Philology and a doctor's degree in Romance Philology at Santiago de Compostela University. From 1976 to 1990, she worked as a teacher of Secondary Education in A Coruña. She usually collaborates with several associations such as the Galician Sociopedagogic Association and the Association of Writers in Galician Language.
She is the author of several studies, essays and linguistic research works.
Pilar García Negro was the first nationalist woman who entered the Galician Parliament (1989). She has been a Member of Parliament since 1989 and member of the standing committee of the 'BNG' National Council.