Method of the study: A descryptive, retrospective study on 32 cases with the omission of pneumothorax in 3 years 2006, 2007, 2008.Results: Our study, on 32 cases missing the diagnosis, shows that clinical symptoms aren't pay attention to exploit, although these factors are often mention in the literature: chest pain (28.5%), dyspnea (65.5%), inflated chest (0%), triade of Gaillard (percussion and trill aren't totally missing).