We describe two new species of Ischnocnema from the states of Minas Gerais and Espírito Santo, southeastern Brazil, based on morphological, bioacoustical, and molecular data. We use three mitochondrial and two nuclear genes in Bayesian inference and maximum likelihood analyses to assess their phylogenetic placement within the I. guentheri series. The two new species group with I. oea in a well-supported clade in both analyses and have a calcar tubercle that is at least as long as wide. This type of tubercle seems to be a putative synapomorphy for the clade. We provide a revised diagnosis for the I. guentheri series, with characters shared by all its members, and discuss the close relationship between the I. parva and the I. guentheri series.