Pathology is the scientific study of diseases. It is a field that bridges clinical practice with the basic sciences. Pathology encompasses a wide subject area and is, therefore, sub-categorized into the disciplines of histopathology, hematology, and chemical pathology.

It is involved in teaching and learning pathology for undergraduates students, and in the near future, the department hopes to provide diagnostic services to patients admitting to the professorial unit of Teaching Hospital, Rathnapura. The department is in the process of establishing a histopathology laboratory and a museum of pathological specimens, which will be used for undergraduate teaching.