A 35-year-old diver noticed hearing loss and tinnitus after his diving holiday. He presented to the Lübeck clinical practice for divers, and we found vascular injections on the eardrum. Audiometry showed a high-degree hearing loss of 40-60 dB. Under the assumption of a perilymphatic fistula, we performed a tympanoscopy with covering of the oval and round windows. Bone-conduction hearing improved immediately postoperatively to 25 dB. A postoperative rheological infusion treatment was given. After 6 months the diver was assessed fit to dive with almost normal inner ear function.