He was discharged in 1916, resuming private medical practice until 1922 when he was again conscripted during the Greco-Turkish War to serve in the Army Hospital of Athens.

During his tenure at the university, he taught and assisted many young doctors in their studies including future politician Grigoris Lambrakis.

When Greece capitulated to Nazi Germany after the "Battle of Greece" during World War II, Logothetopoulos, who spoke the German language fluently, had been the chairman of the Greek-German Council[1] and was married to the niece of Field Marshal Wilhelm List,[2] was appointed Vice President and Minister of Education in the first collaborationist government of Gen. Georgios Tsolakoglou.

After Tsolakoglou was removed from office, he served as Prime Minister between 2 December 1942 and 7 April 1943, when he was replaced by Ioannis Rallis.

He lived with his wife and daughter in the small Bavarian town of Vilshofen an der Donau, where he exercised as a doctor.