Scholastica was born around 480 in Nursia (modern Norcia), Umbria, traditionally identified as Benedict's twin sister. From an early age she was dedicated to God, and she eventually established a community of women religious near Monte Cassino, following her brother's Rule adapted for women.

Gregory the Great, writing in his Dialogues around 593, provides the only detailed account of Scholastica's life — and it is a single scene. Once each year, brother and sister would meet at a house between their two monasteries to spend the day in spiritual conversation. On what proved to be their final meeting, as evening approached and Benedict prepared to return to Monte Cassino (his Rule forbade monks to spend nights away), Scholastica begged him to stay so they could continue their discussion of the joys of heaven.

Benedict refused — he could not break his own Rule. Scholastica laid her head on her hands and prayed. Within moments, a violent thunderstorm erupted so fierce that Benedict could not leave. 'God forgive you, sister,' he protested. 'What have you done?' She replied: 'I asked you and you would not listen; I asked my God and he did listen.' They spent the night in holy conversation. Three days later, Benedict saw his sister's soul ascending to heaven in the form of a dove.

Scholastica died around 543, and Benedict had her buried in the tomb he had prepared for himself at Monte Cassino. He was laid beside her when he died shortly after. Gregory drew the moral: 'She was more powerful because she loved more.' Through her, the Benedictine charism was extended to women, ensuring that the monastic tradition would shape both sexes equally across the centuries.

Scholastica became venerated as a saint, particularly in the Benedictine tradition. Hagiographic narratives emphasize her spiritual authority, her sisterly counsel to Benedict, her prayers' miraculous power (rainstorm), and virtuous conduct as abbess.