Despite many taxonomic revisions, systematic relationships among members of the genus Dendrobates remain poorly understood, particularly the connections between taxa in Amazonia and those in northern South America and Central America. We combine new mitochondrial sequence data with data from previous analyses in order to investigate the relationships among Dendrobates from each major biogeographic region. We address the phylogenetic position of taxa not included in previous molecular systematic analyses, including Dendrobates flavovittatus, D. duellmani, D. galactonotus, D. mysteriosus, and a new Dendrobates, species from Brazil. We attempt to resolve relationships among former members of the genus "Minyobates," and we consider the biogeographic and behavioural implications of the overall tree topology.