Retrospective Cohort Study. This study measures the subcutaneous fat index (SFI) of the cervical spine in patients with spinal cervical spondylosis using cervical magnetic resonance imaging and explores its relationship with neck pain in patients with spinal cervical spondylosis. In this single-center retrospective study, 298 patients hospitalized for spinal cervical spondylosis between January and June 2021 were initially considered. After applying inclusion and exclusion criteria, 93 patients were enrolled. The cervical magnetic resonance imaging data for these patients were analyzed using A-Site software. The SFI was measured at the median sagittal plane on T2-weighted images. Patients were categorized into 2 groups based on their admission complaints: those with cervical pain and those without it. Differences between these groups were then statistically analyzed. The mean SFIs with standard deviations for the neck and non-neck pain groups were 36.4%±7.7% and 27.0%±7.9%, respectively, with a significant difference (P < 0.0001). The SFI was consistently higher across all neck segments in the neck pain group compared to the nonneck pain group (P < 0.05). The 2 groups had no statistically significant difference in the body mass index. The SFI provides a more precise assessment of muscle and fat distribution in the posterior cervical region than body mass index and is generally higher in patients with spinal cervical spondylosis who experience neck pain. These findings suggest the importance of early functional exercises postsurgery for potentially improving surgical outcomes in this patient population.