a These authors contributed equally to this work.Abstract. [Purpose] This study examines the relationship between the range of flexion-extension motion (RFEM) of the cervical spine and skin temperature differences of the right and left sides of the upper trapezius (UT), TB (triceps brachii), PM (pectoralis major), and BB (biceps brachii) regions in patients with cervical herniated nucleus pulposus (HNP). Another aim was to identify the differences between patients with HNP and normal subjects in the RFEM of the cervical spine and skin temperature differences of the right and left sides of the UT, TB, PM, and BB regions.[Subjects] A total of 15 patients with cervical HNP (mean age, 35.8±6.0 years; age range, 28-43 years) and 15 normal subjects (mean age, 33.6±7.95 years; age range, 25-40 years) volunteered to participate in this study.[Methods] The RFEM of the cervical spine for both the HNP and control groups was obtained through lateral radiograph. The average temperature differences between the right and left upper body surfaces were also obtained in the UT, TB, PM, and BB using digital infrared thermographic imagine (DITI). [Results] There was a strong negative correlation between REFM and skin temperature differences of the right and left sides of the UT, TB, and BB in the HNP group. In addition, the HNP group demonstrated statistically significantly lower RFEM and greater thermal asymmetry in all measured body surfaces compared to the control group. [Conclusion] The results from the present study suggest that the use of DITI appears to be a useful and noninvasive approach in the diagnosis of cervical HNP.