We hypothesized that flexion extension (FE) films do not facilitate the diagnosis or treatment of ligamentous injury of the cervical spine after blunt trauma. From January 2000 to December 2008 we reviewed all patients who underwent FE films and compared five-view plain films (5 view) and cervical spine CTC with FE in the diagnosis of ligamentous injury. There were 22,929 patients with blunt trauma and of these, 271 patients underwent 303 FE films. Average age was 39.6 years, Injury Severity Score was 10.8, Glasgow Coma Score was 14.1, lactate was 2.6 mmol/L, and hospital length of stay was 6 days. Compared with FE, 5 view and CTC had a sensitivity of 80 per cent (8 of 10), positive predictive value of 47.1 per cent (8 of 17), specificity of 96.55 per cent (252 of 261), and negative predictive value of 99.21 per cent (252 of 254). For purposes of analysis, incomplete and ambiguous FE films were listed as negative; however, 20.5 per cent (62 of 303) were incomplete and 9.2 per cent (28 of 303) were ambiguous. Management did not change for the 2 patients with missed ligament injuries. The 303 studies cost $162,105.00 to obtain. FEs are often incomplete and unreliable making it difficult to use them to base management decisions. They do not facilitate treatment and may lead to increased cost and prolonged cervical collars.