Abstract The aim of this study was to identify relevant factors associated with sagittal malalignment, which refers to the loss of lordosis or recurrence of kyphosis following an anterior cervical approach. Degenerative cervical kyphosis has increasingly attracted clinical attention, but there are few studies about the classification of local kyphosis and risk factors of adverse sagittal alignment (ASA) after anterior surgery. The study retrospectively reviewed 82 patients with degenerative cervical myelopathy and local kyphosis who underwent anterior cervical discectomy and fusion (ACDF) between January 2019 and December 2021. The patients’ baseline characteristics and postoperative assessments were reviewed using electronic medical records from a single-institution database. Based on the postoperative ASA, the patients were divided into the maintaining and adverse groups. Bivariate and multivariate statistical analyses were performed to predict related factors of the ASA. Comparing the two groups, advanced age (p = 0.019), the classification of local kyphosis (p = 0.001), and preoperative thoracic 1 (T1) slope angle (p