Prior to the appointment she was Head of the Department of Plant Sciences and a member of the University Grants Commission of Sri Lanka.

[1] She vacated the position of Vice Chancellor when she assumed duties as the Chairperson of the University Grants Commission in 2013.

Hirimburegama was born and raised in Colombo, her parents were Professor P. B. Sannasgala, noted oriental scholar and Nalini Ratnayaka, daughter of Abeyratne Ratnayaka, first Cabinet Minister of Food, Co-operatives and later Minister of Home Affairs.

In the same year she left for Belgium to join the Catholic University of Leuven for her PhD.

[2] She and her husband returned to Sri Lanka in 1989 and joined the Botany Department in Colombo University as a Senior Lecturer in January, 1990.