A 27-year-old flight instructor experienced 5 to 10 minutes after a scuba-dive to 29 m, which lasted totally 50 minutes, dizziness, nausea and severe vertigo. The symptoms lasted about an hour. The patient vomited several times and noted sudden onset headache and vertigo lasting the following three days. Hyperbaric oxygen therapy was started 30 hours after the event because decompression sickness was suspected. Transthoracic echocardiographic evaluation showed a patent foramen ovale. Diving accidents may be caused by decompression sickness, the formation of a free intravascular gas phase (bubbles) may result in transatrial shunting in the presence of a patent foramen ovale and may lead to neurological signs and symptoms. In this context the diver was advised to undergo closure of the atrial septal defect. Five months after the incident the patient underwent successful transcatheter occlusion of the PFO.