The first cladistic analysis to determine the monophyletic status of alticine and galerucine leaf beetles and their relationship to one another is provided. A classification based on their hypothesized relationships is proposed. Fifty morphological characters of adults were analyzed from twenty-nine taxa representing six traditionally recognized subfamilies (Orsodacninae, Aulacoscelidinae, Eumolpinae [including Synetini], Chrysomelinae, Galerucinae, and Alticinae), with an emphasis on thorough exemplar representation from galerucines and alticines. Cladistic analyses of these characters using the heuristic analysis of PAUP resulted in 444 equally most parsimonious cladograms, a consensus of which was mostly unresolved. Successive approximations weighting of these trees produced a nearly fully resolved hypothesis of relationships among the taxa. This hypothesis indicates the monophyly of chrysomelines + eumolpines + orsodacnines and monophyly of galerucines + alticines. Importantly, the alticines are a highly derived, strongly supported monophyletic group, nested within galerucines. Therefore, alticines must have a lower relative taxonomic rank (such as tribe) to Galerucinae in order to reflect this phylogenetic hypothesis.