We undertook this study to identify causes of false-negative cervical spine plain radiographic interpretations in a series of experimental readings. One hundred eighty-nine examinations (three views), including 97 patients with acute injuries and 92 normal controls from the same emergency room population, were presented to 14 radiologists. The false-negative rate was 17% (2646 readings). The most frequently missed injuries were laminar fractures, atlantoaxial subluxations, pillar fractures, and fractures of C1 and C2. Analysis of 38 cases with 47 fractures missed by two or more readers showed that 20 (43 %) involved the C1-C2 area, and 14 (30%) involved the laminae and articular pillars. Analysis revealed one or more possible contributing causes for the diagnostic error in 21 injuries: marked osteopenia (2), overlying structures (4), a combination of overexposure and overlying structures (2), and satisfaction of search (13). For 26 injuries (55%), no extrinsic cause was evident, and 23 of these (88%) involved the C1- C2 region or the laminar/articular pillar region.