We present phylogenetic analyses of 42 new partial mitochondrial-DNA sequences in combination with 28 previously published sequences representing all eight major groups of the lizard clade Iguanidae (sensu lato). These sequences include 1838 aligned positions (1013 parsimony informative for ingroup taxa) extending from the protein-coding gene ND1 (subunit one of NADH dehydrogenase) through the genes encoding tRNA^Ile, tRNA^Gln, tRNA^Met, ND2 (NADH dehydrogenase subunit two), tRNA^Trp, tRNA^Ala, tRNA^Asn, tRNA^Cys, tRNA^Tyr, to the protein-coding gene COI (subunit I of cytochrome c oxidase). These data, analyzed in combination with 67 previously published morphological characters, provide statistical support for monophyly of iguanid clades Corytophaninae, Crotaphytinae, Hoplocercinae, Iguaninae, Oplurinae, and Phrynosomatinae. Monophyly is neither supported nor statistically rejected for Polychrotinae and Tropidurinae. Polychrotinae* and Tropidurinae* may be recognized as metataxa, to denote the fact that evidence for their monophyly is equivocal, or replaced by recognizing constituent groups whose monophyly has stronger empirical support. A phylogenetically (non-ranked) based, statistically robust taxonomy of iguanian lizards is proposed. The Old World lizard clade, Acrodonta, is composed of Chamaeleonidae and Agamidae* with the Agaminae, Amphibolurinae, Draconinae, Hydrosaurinae, Leiolepidinae, and Uromastycinae nested within Agamidae*. The predominately New World clade, Iguanidae, contains the groups Corytophaninae, Crotaphytinae, Hoplocercinae, Iguaninae, Oplurinae, Phrynosomatinae, Polychrotinae*, and Tropidurinae*; with Anolis, Leiosaurini (composed of the Leiosaurae and Anisolepae), and Polychrus as the subgroups of Polychrotinae*; and Leiocephalus, Liolaemini, and Tropidurini as the subgroups of Tropidurinae*.