Xenopus laevis (Daudin, 1802) has been the subject of numerous studies but is taxonomically poorly understood. Part of the Cytochrome b gene in mitochondrial DNA was sequenced from 50 individual Xenopus from three currently recognised species, taken from 28 localities in southern Africa, and from an outgroup of two West African X. epitropicalis. Phylogenetic analyses of these data reveal well-supported tree structure, demonstrating three clades within what is currently regarded as X. laevis : X. l. laevis from the Cape, X. l. petersii, and X. l. laevis from further north. This evidence agrees with other studies (on morphology, call and parasite data) which suggest that what is currently regarded as X. laevis encompasses more than one species. Workers using Xenopus collected away from the Cape of South Africa are not safe in assuming that they are using X. laevis.