Engystomops freibergi is a frog native to the Amazonian Brazil, southeastern Peru, and Amazonian Bolivia. For a while, it was considered to be a synonym of Engystomops petersi, its sibling species, but its species status was resurrected in a study published in 1998. Nevertheless, these two species have also been mixed in later studies, and there are records from the Guianas that have not yet been allocated to either species. Divergence of these two species seems to have been driven by behavioural isolation related to male call characteristics more than geographic isolation.