The department was created in December 1999 on the basis of pre-existing separate departments of “Internal non-infectious diseases”, “Pathology” and “Pharmacology, general therapy and toxicology.” Head of Department “Internal non-infectious diseases” from its creation until 1999 was prof. Georgi Mihailov. Head of the department “Pathology” from its inception until 1999 was prof. Vasil Ivanov, and on Department of “Pharmacology, Toxicology and general therapy” from its inception until 1999 manager is prof. Boris Georgiev. Since 1999 and now head of the Department is prof. Geno Angelov. In 2004, the composition of the department quit disciplines on Pathological Physiology and Immunology, and in their place come disciplines Toxicology and Dietetics, and in 2008 the department quit disciplines Common pathological morphology and Special pathological anatomy. In 2015, the department includes the disciplines of Common pathological morphology and Special pathological anatomy and currently in the department are studied 12 disciplines (11 mandatory and one optional) – Propaedeutics of Internal diseases, Pharmacology with Pharmacy, Common pathological morphology, Special Pathological Anatomy, Pharmacotherapy, Toxicology, Internal non-infectious diseases, Dietetics, Clinical laboratory, Cardiology and part of course of Game diseases.

At this stage in the department work two professors, two associate professors and five chief assistant professors and one organizer learning activity.
In 2006, the department was opened two modern laboratories: Clinical laboratory, equipped with automatic hematology analyzer, semi-automatic spectrophotometer and research microscope equipped with a digital camera and computer configuration and a functional room, equipped with ultrasound, gastroscope and 12 – channel electrocardiograph.