We describe for the first time a potential stridulatory apparatus in Oxyporinae rove beetles (Coleoptera: Staphylinidae), which was found in all 18 studied species of the genus Oxyporus and only in three out of six studied species of the genus Pseudoxyporus. No potential stridulatory structures were found in two species of Oxyporus larvae, which we examined. We describe in detail and illustrate these potential stridulatory organs of the following species: Oxyporus mexicanus Fauvel, O. maxillosus Fabricius and O. japonicus Sharp; Pseudoxyporus cyanipennis (Kirshenblat), P. dybowskii (Solsky) and P. melanocephalus (Kirshenblat). Stridulatory structures observed in Oxyporus species involve a potential scraper on the profemur and a potential stridulatory file on the mesocoxae, while Pseudoxyporus differs in having the potential scraper on the procoxae. The specifics of the mechanics and function of this structure in Oxyporinae are unknown but we discuss the various possibilities including association with their subsocial behaviour. The systematic implications of our discoveries for the generic classification of Oxyporinae are discussed. In particular, our findings shed light on the systematic position of Oxyporus smithi Bernhauer, a species from Mexico with ambiguous affinities.