We used phylogenetic analysis of three different genomic regions (parts of the 18S nRNA gene and of the 12S and 16S mtRNA genes), singly and in combination, to position the Orthoptera within the Polyneoptera and to examine the higher systematics of the Caelifera. Analysis of the Ensifera was hindered by the fact that all the grylloid sequences are highly divergent and do not align readily with those of other orthopterans. Within the Polyneoptera the Orthoptera form a clade together with the Phasmida and Embiidina, which are their closest relatives. Both the Ensifera and the Caelifera are monophyletic groups. We propose the following division of the Caelifera into superfamilies, corresponding to the major branches of their phylogenetic tree: Tridactyloidea, Tetrigoidea, Eumastacoidea, Trigonopterygoidea s. nov. (including the Xyronotidae), Tanaoceroidea, Pyrgomorphoidea, Pneumoroidea, and Acridoidea s. nov. (including the Pamphagidae). The question as to whether the Proscopiidae are a component of the Eumastacoidea or a separate superfamily is not resolved. The classical families within the Tridactyloidea, Tetrigoidea, and Eumastacoidea are supported as unitary clades, as are some but not all of the traditional subfamilies of the Acrididae and Romaleidae. The oldest clades within the Acridoidea appear to be some lentulids, the Oedipodinae, and the Abracrini of the Ommatolampinae. Most of the acridoid clades, however, appear to have arisen more or less simultaneously at a slightly later date, and their branching order is not resolved in our analysis. We find little phylogenetic support for dividing the Acridoidea into more than one family.