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 Hindi term for black fever), a protozoal infection. His “Treatise on Kala-azar” is a premier work on the subject.