The scorpion genus Diplocentrus Peters, 1861, comprising more than 50 species, most of which are endemic to Mexico, is the most diverse in the family Diplocentridae Karsch, 1880 (Santibáñez-López et al., 2011). Hoffmann (1931) divided the Mexican species into two groups, the whitei group and the keyserlingi group, based largely on differences in size and coloration. Francke (1977) redefined these groups. The whitei group, renamed the mexicanus group because it included the type species of the genus, comprised species with short cheliceral fingers and the pedipalp femur wider than high. The keyserlingii group comprised species with long cheliceral fingers and the pedipalp femur higher than wide. Several new species of Diplocentrus were since described, but no attempt was made to synthesize the taxonomy of the species assigned to either group or further clarify the validity of the groups. In the present contribution, the species of Diplocentrus with the pedipalp femur higher than wide are reviewed. An operational diagnosis is provided for the keyserlingii group. Diplocentrus formosus Armas and Martín-Frías, 2003, previously synonymized with Diplocentrus tehuano Francke, 1977, is reinstated. Revised, updated diagnoses are provided for all previously described species and three new species, Diplocentrus kraepelini, n. sp., Diplocentrus sagittipalpus, n. sp., and Diplocentrus sissomi, n. sp., are described. The female of Diplocentrus mitlae Francke, 1977, is described for the first time. A dichotomous key is provided for identification of the 10 species in the keyserlingii group.