Zajączkowski was a historian and turkologist who was interested not only in language and literature but also in traditional culture, which was not so popular among colleagues of his own generation. He conducted ethnographic research among Turkish peoples in a very professional manner. The most important of his works concern the Tatars of Dobruja and the Gagauz people. His main monographs are dedicated to these two groups, their language, literature, traditions and rituals. Today, Zajączkowski’s works are extremely valuable and unique.