The cervical spines of 59 adults were examined by means of functional roentgenograms. They were divided into two groups consisting of 28 healthy adults and 31 patients who had sustained soft tissue injury to the cervical spine and who were complaining of neck pain. Roentgenographic lateral views were taken in active flexion and extension as well as in passive maximal flexion and extension. Measurements using the techniques of Penning and Buetti-Bauml were made by three observers independently. There was a highly significant difference between the active and passive segmental ranges of motion in healthy adults. Based on the normal values obtained in this study, 19 hypermobile segments could be diagnosed during the active examination, while 31 hypermobile segments were found during the passive examination. In addition, the active examination found 60 hypomobile segments, while the passive examination showed only 43 hypomobile segments. The Penning Method of measurement was found to be more reliable than that of Buetti-Bauml. If possible, the functional roentgenogram examination of the cervical spine in the sagittal plane should be performed by including passive movement and the range of motion should be compared with the normal values obtained by passive examination.