The Authors report the case of a fifty-nine-year-old patient, affected by complete eventration of the left diaphragm and cranial stomach dislocation with axial volvulus, associated with an upward movement of part of the left colon and some jejunal loops. The subclinical condition had been occasionally discovered during a routine chest X-ray at the age of eighteen and the patient remained without symptoms up to five years ago, when he began to show significant digestive and cardiorespiratory symptoms. The patient has been successfully treated via thoracotomy with phrenic alloplastic using Gore-Tex patch and has obtained an immediate remission of the symptoms. Left diaphragmatic eventration of the adult is a rare pathology, either congenital or acquired, with few and definite surgical indications such as severe digestive and cardiorespiratory symptoms. Different surgical techniques including the use of patches are herein illustrated.