The aim of the paper is to describe the functions of anthroponyms with an ethnic attribute in ethnic jokes. Based on the excerption of such anthroponyms from 404 Slovak and 507 American ethnic jokes and a subsequent analysis, we assign three specific functions to these proper names - formal, ethno-referential, and compositional function. The presence of an ethnic specific anthroponym turns a joke into an ethnic joke in the broadest sense and regardless of its topic. Moreover, these anthroponyms refer the recipient to a specific ethnic group with its typical as well as stereotypical features and characteristics. Finally, these expressions may take an active part in the creation of the punchline via a play on words.