Orbeli played an important part in the development of evolutionary physiology and wrote more than 200 works on experimental and theoretical science, 130 of them journal articles.

He graduated from the Gymnasium in Tbilisi in 1899 and entered the Imperial Military Medical Academy in Saint Petersburg.

For the next thirty-five years, Orbeli's life and scientific career were closely connected with the work of Pavlov.

Orbeli worked for two years abroad, with Ewald Hering (1834–1918) in Germany, John Newport Langley (1852–1925) and Joseph Barcroft (1872–1947) in England, and at the Marine Biological Station in Naples.

It was later renamed I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry of the Academy of Sciences of the Soviet Union.