Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) ; Processo FAPESP: 06/02778-5 ; Processo FAPESP: 05/52608-6 ; The phylogenetic position of Triatoma sherlocki within triatomines group was inferred by analyzing mtDNA fragments of Cyt B and 16S ribosomal RNA by using maximum parsimony and Bayesian analysis. Despite being differentiated from members of the T brasiliensis complex on morphologic grounds, molecular phylogenetic analysis suggests T sherlocki is a member of this complex; moreover, it was placed as a sister species of T melanica. These suggestions were supported by robust credibility rates. Hence, we show evidence for the paraphyletic group of the "Triatoma brasiliensis complex," which should be composed of T.brasiliensisbrasiliensis, T.brasiliensismacromelasoma, T.juazeirensis, T.melanica,and T.sherlocki.