 Jagendorf became an Assistant professor at Johns Hopkins University in 1953, as Associate professor in 1958, and a Full professor in 1966.Jagendorf then returned to Cornell University as Professor of Plant Physiology, and in 1981 became the Liberty Hyde Baily Professor.Since 1997 Jagendorf has been the Liberty Hyde Bailey Professor Emeritus in the Department of Plant Biology and was actively doing research until days before his death.