It was started on the 02 July 1960 by the then Prime Minister Sirimavo Bandaranaike, as a Base Hospital.

Spread on 18 acres of land, the hospital did a great service, particularly to the people of Dehiwela-Mt. Lavinia. Subsequently it was upgraded to a General Hospital and later to a Teaching Hospital. 

It became the Teaching Hospital for the medical students of the Faculty of Medical Sciences in The University of Sri Jayawardanapura. Since then it has become increasingly popular and now people from all parts of the island come here for treatment.

The hospital is also playing an increasingly important role in the training and teaching of postgraduate trainees in the medical specialties.

The training of nurses, paramedical staff and technicians are also part of the hospital's work.

The Sri Jayawardanapura National Nursing School was started in 1998, and has taken 3 batches of 100 nurses so far. These student nurses will begin their hospital training next year. Their clinical supervision and examinations will also be held here.

A modern Endoscopy Unit was also started in the hospital and is now a very busy, vibrant unit doing a great service to patients.

In 1997 a large amount of valuable medical   equipment were donated by the Japan-Sri Lanka Friendship Association.

In 1998 a fully equipped auditorium was made. This is situated in a new 3 storey building which also has the JMO offices.

An eight storey building and a theatre complex with 6 new theatres has been built. These will function next year, greatly increasing the services to the public.

The foundation stone was laid for a 4 storey building for a new Psychiatry Unit in 2001.

There is a plan for another building to house the radiology unit, laboratory services and the finer specialties, which will start in 2001.

A paying ward is also planned for in the near future.