The monastery was founded by St. Gregory of Mount Athos (Younger) in the fourteenth century when he came to Mount Athos to pursue asceticism. By the end of the 15h century, according to the Russian pilgrim Isaiah, the monastery was Serb. Over the next several centuries little is known about the monastery other than that it suffered serious damage from raiders and in 1761 from a fire. Barsky, an eighteenth century Russian visitor, observed that restoration work had been done in 1500, and also noted that the fire of 1761 had destroyed many of the heirlooms and documents then held by the monastery. Additional damage was incurred during the Greek revolution against the Turkish sultan in 1821. Restoration work at Gregoriou monastery that had been accomplished over the years was supported by various benefactors including the princes of Moldavia, Phanariotes, archbishops of Hungro-Wallachia. Even a few Turkish sultans provided aid.
The katholikon, dedicated to St. Nicholas, was built in 1768 and follows the Athonite style. The frescos in the katholikon were done in 1779 by the monks Gabriel and Gregory from Kastoria. The frescos present scenes from the Old Testement. A narthex was added to the katholikon in 1846, under the direction of Neofitos, the abbot. The monastery also contains ten chapels as well as four cells in the administrative center Karyes.