The majority of undiagnosed diaphragmatic ruptures are associated with a high mortality rate if not treated immediately. A high index of suspicion for diaphragmatic injury during initial evaluation is the most important factor. A case was experienced involving delayed presentation of a traumatic diaphragmatic hernia, in a 49 year old female injured in a road traffic accident a year prior to admission. She was admitted with complaints of left side chest pain, nausea, and vomiting for 7 days. She was diagnosed as a diaphragmatic hernia on her left side by several diagnostic tests including a gastroscopy and CT scan. Her medical history was carefully examined as well. Surgical repair was performed. (Korean J Gastrointest Endosc 2000;20:46~48)