The Parasitic Diseases Research Unit (PDRU) was previously known as Malaria Research Unit (MRU). This was established in 1988 in the Department of Parasitology of the Faculty of Medicine, University of Colombo by Professor Kamini Mendis. MRU functioned as a Centre for post-graduate research training and malaria research on Immunology, Molecular biology, Epidemiology as well as Genetics. The main collaborators who were responsible for setting up the initial scientific programmes were Prof. Richard Carter from the University of Edinburgh, UK and Dr. Peter David from the Institute Pasteur, France. To date,32 post-graduate degrees have been awarded from the research training received through the Malaria Research Unit.  The MRU has also provided opportunities for several under-graduate students of the University of Colombo as well as other Universities both local and overseas to conduct their short-term research studies. The MRU was linked to Malaria Field Research Station (MRS) at Kataragama. This Research Station was established at Mailagama in Kataragama, in collaboration with Dr Pushpa Herath, who was the Senior Entomologist of the Anti-Malaria Campaign, Ministry of Health at the time. This research station has served as a focus for a number of major epidemiological studies, including the insecticide-impregnated bed nets project and the village-based malaria diagnosis & treatment centres.  Currently this research station is known as Population Health Research Center and is being used to carry out field research with regard to all parasitic diseases. Staff of the Department of Parasitology, Faculty of Medicine, University of Colombo along with scientists from other Faculties of the University of Colombo as well as other Universities and Research Institutions both local and foreign used to conduct research work at the MRU in relation to malaria. From 1998 to 2003, the MRU was directed under the guidance of Dr.Shiroma Handunnetti, who was the first research student to receive a PhD degree through research training at the MRU. Thereafter Dr.Deepika Fernando (2003 – 2004) and Dr.Sisira Pathirana (2004 – 2005) functioned as Coordinators.

Research studies at the MRU have been carried out with research grants received from various organizations both local as well as overseas such as the National Science Foundation of Sri Lanka, the National Research Council of Sri Lanka, the World Health Organization (TDR), the International Foundation of Science and the World Bank. In addition to the research programmes, the Malaria Research Unit provided free laboratory diagnostic services for malaria to hospitals under the Ministry of Health in Colombo including the National Hospital of Sri Lanka (NHSL), Lady Ridgeway Hospital (LRH) for children, De Soyza Maternity Hospital (DMH), Castle Street Hospital and the Military and Police Hospitals.

Since March 2005 the MRU came under the purview of the Head, Department of Parasitology until the change of its name to PDRU. The PDRU conducts research mainly on Leishmaniasis in several areas including epidemiology, parasite and host genetics, immunology and vector studies, in collaboration with world renowned research facilities. The PDRU continues to provide research training for post graduate trainees as well as the other services which were provided by the MRU previously.