He conducted numerous excavations studying Mycenean and classical Greek antiquities during the early 20th century, including excavations at the Agora of Athens, the palace of Mycenae[1] and at Thebes.

Among other things, he became known as a proponent of the theory of an autochthonous Greek origin of the Vlachs in Greece.

[3] In 1911, Keramopoulos excavated part of a large peristyle complex in the Agora of Athens, which may have been the city's Prytaneion.

[4] In 1926, he excavated a medieval cemetery in Thebes, making in the process the earliest known study of post-Roman pottery in Greece.

[5] 1952, he was appointed by John Papadimitriou to a committee overseeing the excavation of Grave Circle B at Mycenae, which had been discovered the previous year.