Lucumí is a term here used to refer to a language spoken in Cuba by practitioners of the religion known as Santería. In Cuba both the santeros and the language are often called Lucumí, a form of which the origin has been discussed by William Bascom. Bascom seems to have been the first to assert positively that Lucumí is derived from Yoruba, a language of southwestern Nigeria. This view is supported by the folklore of Lucumí-speakers, which often contains propositions like these: Lucumí is Yoruba; Lucumí and Yoruba are the same thing; Lucumí is a dialect of Yoruba; Lucumí is a mixture of Yoruba dialects. Other writers have rejected the classification of Lucumí as related to Yoruba in the usual sense, and have called Lucumí a pidgin language. The purpose of this paper is to test Bascom's hypothesis by the comparative method—specifically, by investigating phoneme correspondences in cognate items.