Cytogenetic analyzes were carried out on populations of Pachycondyla harpax (Fabricius, 1804) (Hymenoptera: Formicidae: Ponerini) in southern Bahia, Brazil. The chromosome number was variable with 2n = 90–92, and the chromosomes, predominantly acrocentric, were characterized by being small in size. The karyotype formulas of the studied populations were: Ilhéus 2K = 16M 76A, Una 2K = 16M 74A and Belmonte 2K = 16M 76A. The karyotype of a fourth population (Igrapiúna) was undetermined. Fluorochrome banding shows the presence of heterochromatic blocks rich in GC in the pericentromeric region of one of the metacentric pairs, indicating the nucleolus organizer regions. The first case of a diploid male in the genus Pachycondyla is reported.