Coeliac disease is usually revealed by intestinal symptoms, but less frequently by deficiency symptoms. Early screening is very important to avoid with appropriate diet an intestinal lymphoma or epidermoid cancer. We report here the case of a 68-year old woman where coeliac disease was pointed out by very long Prothrombin Time (PT) and Activated Partial Thromboplastin Time (APTT). Clinical examination was strictly normal except for leanness, a small height, and several diarrhoea episodes 3 or 4 times a year. Other blood tests showed a macrocytic anemia, a fibrinogen level slightly above the upper limit, a decreased proteinaemia and albuminaemia, and a sideraemia at the lower normal limit. Liver tests pointed to a cytolysis. Vitamin K-dependent factors were decreased. A perfusion of vitamin-K allowed getting a normal PT. Duodenofiberscopy with biopsy allowed the diagnosis of coeliac disease. Neither lymphoma nor epidermoid cancer were detected. A gluten-free diet allowed the disappearing of digestive symptoms, weight rising and return to a normal PT. Searching for a coeliac disease is therefore relevant in aged patients even when very faint clinical or biological symptoms of malabsorption appear, particularly when PT is longer than the control with decreased vitamin-K dependant factors.