[1] Premasiri's academic training represents a synthesis of both the Buddhist and Western philosophical traditions, first at the University of Peradeniya and subsequently at Cambridge and Hawaii.
He received his primary and secondary education from Christian College, a boys' school in Kotte presently known as Sri Jayawardenepura Maha Vidyalaya.
Jayatilleke, Premasiri traveled to the UK in 1965 and studied western ethics and philosophy at the University of Cambridge under notable British Philosophers such as Sir Bernard Williams.
In 1972 the two Buddhist studies departments at Peradeniya were uprooted during the Sri Lankan government's university reorganization.
In 1997, Premasiri became head of the Pali and Buddhist Studies Department and served in this role until 2004, with a one-year research sabbatical in Norway.
Premasiri's academic career can be seen as a synthesis between Western academia and early Buddhist thought.
Though he traveled to the U.K. and to the U.S. to receive academic training, he continually returned to the country of his birth and especially to the University of Peradeniya to serve and teach.
In 1988/89, a Fulbright Scholar-in-Residence Program took him to Colby College in Waterville, Maine, where he served as a visiting professor in the philosophy department.
[22] Besides these organizational involvements, Premasiri has also conducted a Meditation and Pali Text Study Group in Kandy on a regular basis since 1994.