He initially studied architecture, and in 1898 participated in an archaeological dig at Babylon under the leadership of Robert Koldewey (1855–1925). From 1903 to 1914, he directed the excavation of the ancient Assyrian capital of Assur. During this time period, he also performed archaeological excavations at Hatra and Shuruppak. Another significant archaeological site that he was involved in was the Hittite city of Sam'al.
Among his better known writings were Der wiedererstandene Assur, and the autobiographicalLebenserinnerungen eines Ausgräbers (Memoirs of an excavator). Other publications by Andrae include: