The genus Acalymma Barber comprises 72 species widely distributed in America, mainly in the neotropical region. The taxonomy of this genus is in a confused state because of the superficial similarity of all species, which posses similar color patterns and elytral punctation. The significance of mouthpart characters for assessing phylogenetic relationships among subfamilies of Chrysomelidae, and especially the Alticinae and Galerucinae, has been noted by various authors. The present paper is a comparative morphological study of mouthparts based on 14 species of Acalymma. As a result of this study, the taxonomic value of the mouthparts for recognizing species is established.