The karyotype of the addax (Addax nasomaculatus, 2n = 58) has been investigated by RBG and CBG banding techniques. All chromosomes are acrocentric except the first pair of autosomes, which is submetacentric. The X chromosome is the largest acrocentric, and the Y chromosome is a medium sized acrocentric. According to the standard conventions used for cattle and goat, p- and q-arms of the pair of submetacentric autosomes correspond, respectively, to chromosomes # 27 # 1. The comparison of banding patterns of chromosomes in addax and four other species of the subfamily Hippotraginae reveals several common features and a high degree of homoeology with caprine and bovine karyotypes.