The purpose of the study was to evaluate the diagnostic value of pelvic radiography in the initial trauma series when compared to multidetector CT (MDCT) findings in serious blunt trauma. Inclusion criteria were blunt trauma and pelvic radiography in the initial trauma series, followed by a whole-body MDCT. A total of 1386 patients (874 male, 512 female, age 16-91 years, mean 41 years) met the inclusion criteria. Imaging studies were evaluated retrospectively by anatomical region and classified, when possible, using the Tile classification. Based on MDCT, a total of 629 injuries occurred in 226 (16%) of these 1386 patients. Radiography depicted 405 fractures in these 226 patients, giving an overall sensitivity of 55%. In 24 patients (11%) radiography was false-negatively normal. The sensitivity of radiography was mainly good in the anteroinferior parts of the pelvis, fair in the acetabulum and ileum, and poor in the posterior ring. By MDCT 141 (62%) patients were classified using the Tile classification and by radiography 133 patients (59%) were classified. MDCT and radiography showed the same type of pelvic injury in 72 patients (59%) and the subtype in 17 patients (14%). In 48 patients (40%) the pelvis was shown to be stable by radiography but unstable by MDCT. In conclusion, the sensitivity of pelvic radiography is low, and it is not reliable for determining if the pelvic injury is stable or not.