A case of per-surgery discovery of a pneumolabyrinth referred to the oval window is reported. Such was associated with a post-stapedectomy perilymphatic fistula. Revealing clinical signs were invalidating vertigo, transmission-type hearing loss, and tinnitus. Surgical plugging of the fistula caused the dizziness spells to regress completely, as well as improving tinnitus and restoring hearing markedly. Literature data confirm the fact that pneumolabyrinths are always associated with perilymphatic fistulas. Moreover, pneumolabyrinths seem to play an important role in the genesis of cochlear signs accompanying perilymphatic fistulas.