Chronic migraine (CM) patients who report a high frequency and intensity of headaches also report neck pain (NP) and neck disability (ND) in neck activities that require stability. In this context, CM patients may report different headache intensities at different levels of ND. Our aim in this study is to investigate whether the intensity of headaches differs according to the level of ND in CM patients. Headache intensity and NP intensity were evaluated with the Visual Analog Scale (VAS), and ND was evaluated with the Neck Disability Index (NDI). A total of 142 patients who met the inclusion criteria were included in the study. The mean age was 53.24 ± 12.08 years. The median number of monthly headache days was 20. According to VAS, the median headache intensity was 10(4-10) cm and the median of NP intensity was 9(1-10) cm. The mean NDI was 28.45 ± 10.28. There was a difference in headache intensity between mild and severe disability levels ( = 0.007, Z = -3.289); headache intensity between mild and complete disability levels ( = 0.000, Z = -4.421); and headache intensity between moderate and complete disability levels ( = 0.004, Z = -2.212). Although the difference in headache intensity between ND levels is small, a median increase of 2 cm in headache intensity at mild ND levels may result in complete ND. A median increase of 1 cm in headache intensity at the moderate ND level may cause complete disability in the neck. According to our results, the intensity of headaches of CM patients differed according to the level of ND. We consider our results to be clinically important in this context.