Passipassalus brevicornis n. sp. is described from two specimens from Tefé and Coari, Amazonas, Brazil. This species represents the fifth species recognized of Passipassalus and differs from the other species of the genus mainly by having an apex of central tubercle of median frontal structure not free, frontal fossae with some scarce setae, metasternal fossae with scarce setae, humeri fully pubescent, and marginal groove over anterior ventral edge of femur I marked and complete. Additionally, a key to the species of Passipassalus is given.
Keywords: Bess beetle; diversity; new species; taxonomy.