Purpose This study was conducted to verify that the cervical deep muscle flexion exercises (CDFE) benefit on stability in the neck so that the patients would have less pain and better cervical function. Methods The subjects in this study were assigned into an experimental group (EG) of 16 subjects and a control group (CG) of 16 subjects. The CDFE and stretching exercise (SE) were applied to the EG and CG, respectively. And, visual assessment scale (VAS) for pain and neck disability index (NDI) for cervical function were used to assess the subjects before and after the intervention. The subjects performed the exercises 3 times a week for 4 weeks. Results There was a significant difference in variations of cervical pain in between the EG and CG from 25.16 ± 13.29 to 6.38 ± 8.14 mm. There was a significant difference in variations of neck functional disability in between the EG and CG from 4.94 ± 2.17 to 0.25 ± 1.73 point. Conclusion The subjects performed the CDFE for 4 weeks were able to correct the spine alignment and strengthen the muscles around the cervical region, which was able to reduce stress on the neck so that cervical pain was reduced and the neck functional ability was increased.