Objective: To describe changes in the radiographic examination of the chest in patients with post-traumatic diaphragmatic hernia (PTDH) confirmed intra-operatively. Methods: Between January 1990 and August 2008 45 patients with PTDH were treated. We analyzed demographic data, cause of injury, changes in chest radiography (CXR), extent and location of the diaphragmatic lesion and herniated organs. We described the radiographic findings most frequently identified by surgeons and radiologists. Results: CXR was performed on 32 patients, predominantly male (27 cases, 84.4%) and the mean age was 34 years. The most common cause of injury was blunt trauma (25 cases, 78.1%). Radiographic examination of the chest showed changes suggestive of PTDH in 26 cases (81.3%). During exploratory laparotomy, left PTDH was found in 28 cases (87.5%) and right in four (12.5%). The most frequently herniated organ was the stomach. Conclusion: The study showed that CXR is very useful in the initial diagnostic approach to PTDH. The difficulty is that diaphragmatic injuries, particularly after penetrating trauma, may initially go unnoticed, and without changes in the CXR images, diagnosis is made difficult.394280285Shanmuganathan, K., Killeen, K., Mirvis, S.E., White, C.S., Imaging of diaphragmatic injuries (2000) J Thorac Imaging., 15 (2), pp. 104-111Sandstrom, C.K., Stern, E.J., Diaphramatic hernias: A spectrum of radiographic appearances (2011) Curr Probl Diagn Radiol., 40 (3), pp. 95-115Kaw Jr., L.L., Potenza, B.M., Coimbra, R., Hoyt, D.B., Traumatic diaphragmatic hernia (2004) J Am Coll Surg., 198 (4), pp. 668-669Marts, B., Durham, R., Shapiro, M., Mazuski, J.E., Zuckerman, D., Sundaram, M., Computed tomography in the diagnosis of blunt thoracic trauma (1994) Am J Surg., 168 (6), pp. 688-692Aun, F., Lourenção, J.L., Younes, R.N., Alfieri Júnior, F., Birolini, D., Oliveira, M.R., Contribuição ao estudo da história natural e dos fatores de risco das hérnias diafragmáticas traumáticas (1982) Rev Hosp Clin Fac Med Univ São Paulo., 37 (6), pp. 265-270Melo, A.S.A., Moreira L.B.M, Damato, S.D., Martins, E.M.L., Marchiori, E., Ruptura traumática do diafragma: Aspectos na tomografia computadorizada (2002) Radiol Bras., 35 (6), pp. 341-344Grimes, O.F., Traumatic injuries of the diaphragm. Diaphragmatic hernia (1974) Am J Surg., 128 (2), pp. 175-181Madden, M.R., Paull, D.E., Finkelstein, J.L., Goodwin, C.W., Marzulli, V., Yurt, R.W., Occult diaphragmatic injury from stab wounds to the lower chest and abdomen (1989) J Trauma., 29 (3), pp. 292-298Koehler, R.H., Smith, R.S., Thoracoscopic repair of missed diaphragmatic injury in penetrating trauma: Case report (1994) J Trauma., 36 (3), pp. 424-427Campos, L.I., Sipes, E.K., Laparoscopic repair of diaphragmatic hernia (1991) J Laparoendosc Surg., 1 (6), pp. 369-373Kawahara, N., Zantut, L.F., Poggetti, R.S., Fontes, B., Bernini, C., Birolini, D., Laparoscopic treatment of gastric and diaphragmatic injury produced by thoracoabdominal stab wound (1998) J Trauma., 45 (3), pp. 613-614Eren, S., Ciris, F., Diaphragmatic hernia: Diagnostic approaches with review of the literature (2005) Eur J Radiol., 54 (3), pp. 448-459Gelman, R., Mirvis, S.E., Gens, D., Diaphragmatic rupture due to blunt trauma (1991) AJR Am J Roentgenol., 156 (1), pp. 51-57Moore, E.E., Cogbill, T.H., Jurkovich, G.J., McAninch, J.W., Champion, H.R., Gennarelli, T.A., Organ injury scaling III: Chest wall, abdominal vascular, ureter, bladder, and urethra (1992) J Trauma., 33 (3), pp. 337-339Haney, P.J., Whitley, N.O., Brotman, S., Cunat, J.S., Whitley, J., Liver injury and complications in the postoperative trauma patient: CT evaluation (1982) AJR Am J Roentgenol., 139 (2), pp. 271-275Freeman, T., Fischer, R.P., The inadequacy of peritoneal lavage in diagnosing acute diaphragmatic rupture (1976) J Trauma., 16 (7), pp. 538-542Wise, L., Connors, J., Hwang, Y.H., Anderson, J.C., Traumatic injuries to the diaphragm (1973) J Trauma., 13 (11), pp. 946-950Gurney, J., Harrison, W.L., Anderson, J.C., Omental fat simulating pleural fluid in traumatic diaphragmatic hernia: CT characteristics (1985) J Comput Assist Tomogr., 9 (6), pp. 1112-1114Mirvis, S.E., Keramati, B., Buckman, R., Rodriguez, A., MR imaging of traumatic diaphragmatic rupture (1988) J Comput Assist Tomogr., 12 (1), pp. 147-149Ammann, A.M., Brewer, W.H., Maull, K.I., Walsh, J.W., Traumatic rupture of diaphragm: Real-time sonographic diagnosis (1983) AJR Am J Roentgenol., 140 (5), pp. 915-916