In 1870, Israel received his medical doctorate from Friedrich-Wilhelms-Universität in Berlin, where he studied under Ludwig Traube (1818–1876).

During the Franco-Prussian War, he served as a military physician, afterwards furthering his studies in Vienna (1871).

In 1875, after furthering his education in England and Scotland, he was appointed deputy physician-in-chief of the surgical department of the Jewish hospital in Berlin, where, in 1880, he was promoted to chief-in-chief.

[3] He was also an early advocate of Joseph Lister's antiseptic practices in the operating room.

[citation needed] In 1878, he provided the first description of actinomycosis in humans, caused by a pathogen that was later given the name Actinomyces israelii.