The Isolation ward at LRH was started on 16/07/2003 as a ward to isolate children with infectious diseases to face SARS virus infection under WHO guidance. Since then the unit served to isolate and treat patients who had infectious diseases such as Chickenpox, Measles, Mumps, Hepatitis, TB, Influenza etc to prevent transmission to other patients. During the Measles outbreak and the pandemic H1N1 Influenza the Isolation Unit provided care to those patients in its full capacity in the past.

During the present Covid19 pandemic suspected COVID-19 children are admitted to this unit, isolated the PCR testing is done and managed until the PCR result is available. In 2020, with financial assistance from UNICEF and free of charge labour from Sri Lanka Navy it was renovated with improved facilities to provide isolation care in separate rooms with attached bathrooms. It can accommodate 8 patients in separate rooms.