Munchausen's syndrome is classified as a chronic factitious disorder with predominant physical signs and symptoms. Several symptoms are specific to this disorder, such as travelling and pseudologia fantastica. Others symptoms, such as multiple physical complaints with no organic substrate, are shared with somatoform disorders. We report a case showing how difficult it is to diagnose a Munchausen syndrome. We discuss also the opportunity to classify such a syndrome as a factitious disorder. Indeed, several authors suggest classifying Munchausen syndrome as a subtype of somatoform disorders, as those two disorders share a lot of characteristics.