Previous systematic studies, using morphometric, allozymic, and cytogenetic data, have produced conflicting results as to the relationship of Dipodomys elator to other species of kangaroo rats. In this study, phylogenetic relationships of D. elator and other closely related taxa (D. merriami, D. phillipsii, D. ordii, D. spectabilis, and D. nelsoni) were examined using nucleotide-sequence data (1,143 bp) from the mitochondrial cytochrome-b gene. With 1 exception, all parsimony and neighbor-joining analyses (regardless of differential weighting scheme or method of calculating genetic distances) indicated that D. elator is most closely related to D. phillipsii. As a result, it is recommended that D. elator and D. phillipsii be included within the phillipsii species group.