A new, miniaturized species of Phyllodactylus Gray from Guerrero, Mexico is described. The species appears to be the smallest American species of leaf-toed gecko. The diploid karyotype consists of a graded series of 36 acrocentric and 2 subtelocentric chromosomes; the telocentric pair is the second largest. The new form is morphologically very similar to P. duellmani, but is electrophoretically quite distinctive having a genetic distance of 0.839. The new population is also meristically quite similar to allopatric P. bordai, but can be distinguished by its small size at which reproductive maturity is attained and by the number of transverse ventrals.