Immunology has played a prominent role in the history of medicine and considerable research has been conducted to explore the history of this science. However, the use of blood serum to treat diseases in pre-medieval times lacks a well-documented history. Despite this knowledge gap, Emil Adolf von Behring is recognized for his groundbreaking discovery of serum therapy. Serum therapy involves the administration of animal or human blood serums as a means of combating infections, paving the way for more effective disease management in the medical field.This research, citing the book, The Canon of Medicine, written by Avicenna, states that there is evidence suggesting that serum therapy can be seen much earlier than its use in the Western world. In the discussion of poisonous animal bites, Avicenna first states the significance of fortifying the immune system to protect the body. In Avicenna’s work on rabies, he states that if a patient bitten by a rabid dog eats the blood of the rabid dog that bit him, or eats the rabid dog’s liver and heart, or puts it on his wound, especially if the liver and heart belong to the same dog that bit him, the patient will be healed. This early exploration of utilizing animal-derived substances to combat disease may be regarded as an antecedent to contemporary serum therapy, which was later developed by Emil Adolf von Behring.This research reveals that Islamic scholars, especially Avicenna, through their clinical and practical experiences, possessed knowledge of the immune system and serum therapy long before the discoveries of Edward Jenner and Emil Adolf von Behring. Consequently, they were able to successfully apply this knowledge in treating patients well before the formal recognition of these principles in Western medicine.