Karagöz, an important subject of traditional Turkish theater, is a performance art performed by a performer called hayalî/karagözcü for various purposes, especially to entertain adults and children, to ensure unity and solidarity in the public atmosphere, and to convey tradition and culture. Karagöz shadow play is an important culture bearer that can bring people together in public and private places, reflecting the common consciousness of people and entertain them for centuries. Karagöz shadow plays have undergone several changes and transformations in order to reflect its own culture through every period. It is a fact that Karagöz, which is seen mostly for the purpose of entertaining children today, has different functions besides entertaining. Therefore, in this article, Karagöz's functions are examined based on the functional approach determined byWilliam R. Bascom in order to reveal the functions of the Karagöz play. Karagöz plays compiled by the author of this article from different places in 2019 were examined in accordance with Bascom's "Four Functions of Folklore", which has been translated into Turkish that defines four functions as; "entertainment and having a good time (entertainment) function; support of social institutions and ceremonies (affirmation of culture and validation of rituals and institutions by those who observe and perform the rituals); transferring education and culture to younger generations (in all societies and cultures, especially in illiterate cultures) and the function of getting rid of social and personal pressures (maintaining accepted behavior patterns)”. First of all, in this article, a brief information about Karagöz shadow play is given, then a compilation information about four Karagöz shadow plays, one each by hayalî/karagözcü (performers) İshak Ikincitekgül, Ata Taşkan, Deniz Özgökbel and Kemal Atan Gür is given. Following this, the shadow plays in question were examined in accordance with the functional theory determined by Bascom. The places where the audience laughs in the shadow plays are explained with the entertainment function. The parts in which the hayalî/karagözcü (performers) provide information with cultural elements, dialect and dialect imitations, and game contents are explained with the function of cultural transfer. Some expressions of the hayalî/karagözcü (performers)in the play have also been interpreted as the function of getting rid of social pressure. As a consequence, information about the continuation of Karagöz plays still preserving their function today, the necessity of using Karagöz in education, its functions in family and community life, its effect on Turkish language, its role in the preservation and transfer of oral cultural assets, its importance in the development of thinking skills and its effects on social communication, its role in the transmission of the characteristics of different cultures within the field of Turkey were examined.