A phylogeny of lacewing families Ithonidae and Polystoechotidae is presented based on three gene markers (16S and 18S ribosomal DNA and CAD) and 23 morphological characters. Living and fossil genera presently placed in Polystoechotidae (Fontecilla Navás, Platystoechotes Carpenter and Polystoechotes Burmeister) and Ithonidae (Adamsiana Penny, Allorapisma Makarkin & Archibald, Ithone Newman, Megalithone Riek, Oliarces Banks, PrincipialaMakarkin & Menon, Rapisma Walker and Varnia Walker) were included in phylogenetic analyses (parsimony and Bayesian) and compared with outgroups selected from various families of Neuroptera. The resulting phylogeny recovered a monophyletic clade comprising Ithonidae and Polystoechotidae as hypothesized previously. Rapismatidae as a separate family is not supported and Ithonidae are rendered paraphyletic with three extant genera previously placed in Ithonidae (Adamsiana, Oliarces, and Rapisma), recovered deep within Polystoechotidae. The fossil genera Allorapismaand Principialaformed a sister-group relationship with Rapisma, also within Polystoechotidae. Due to the lack of mutually exclusive synapomorphies for either Ithonidae or Polystoechotidae, a single more inclusive family Ithonidae is proposed, including all ithonid genera and all genera previously placed in Polystoechotidae. Synapomorphies characterizing the revised concept of Ithonidae s.l. are discussed.