Rai Bahadur Sir Upendranath Brahmachari was a renowned Indian scientist and a prominent medical practitioner of his era. He had a remarkable personality and his most outstanding research contribution was the discovery of Urea Stibamine, an organic antimonial compound, which played a vital role in the treatment of Kala-azar, a protozoal infection. After gaining a firm foundation in mathematics and chemistry, he decided to study medicine after which he joined the Provincial Medical Service. Later, he was appointed as a teacher at the Campbell Medical School, where he spent the most productive time of his life and performed his groundbreaking research regarding the treatment of Kala-azar. During the years of his service and even after retirement, he remained actively connected to various spheres in the University of Kolkata. He was associated with almost all the known scientific and literary organizations at Kolkata and took a keen interest in humanitarian and cultural activities. He also played a significant role in the formation of the world’s second Blood Bank at Kolkata. He was the founder of Brahmachari Research Institute which became successful in the fields of both research and manufacture of medicine. He was the first Indian to become the Chairman of the Managing Body of the Indian Red Cross Society of the Bengal Branch.