To clarify the effectiveness of Chinese herbal fomentation in treating chronic neck pain by means of changes in cervical kinematics. Seventy-six patients with chronic neck pain were included in the study and were randomized into two groups based on the random number generator of the SPSS software: fomentation combined with Chinese herbal (Group 1) and fomentation without any medicine (Group 2). In both groups, the fomentation lasted for 60 min and heated to 35 A degrees C, once a day for 28 consecutive days. Standard lateral radiographs of the cervical spine were obtained including the neutral, full flexion, and full extension positions. Before and after intervention, the following parameters were used to evaluate the changes in kinematics: range of motion (ROM), sagittal alignment and instantaneous center of rotation (ICR). After treatment, the ROM was signifcantly higher than that of before treatment in Group 1 (51.5, 95% CI: 49.8-55.9; P < 0.05). There was no significant difference between before and after treatment in Group 2 (P > 0.05). Although C2-C7 cervical alignment was increased in both groups after treatment, no significant difference was detected between before and after treatment (P > 0.05). For Group 1, the significant X coordinate variation was only observed at C5/C6 level (38.1; 95% CI: 34.0, 42.1; P < 0.05). There was a significant upward trend in the Y coordinate of the ICR at C5/C6 (-30.5; 95% CI: -34.3, -26.8; P < 0.05) and C6/C7 after treatment (-6.1; 95% CI: -6.7, -5.4; P < 0.05). For Group 2, the ICR location of each level was not statistically different between the pre- and post-treatment (P > 0.05). Chinese herbal fomentation could improve abnormal mobility in terms of ROM and ICR. Chinese herbal fomentation might be an effective treatment for chronic neck pain.