Abstract Background Segmental cervical instability is a risk factor for the progression of osteophytic bone spurs and development of myelopathy, and is treated as a relative contraindication of cervical laminoplasty. The aim of this study was to compare laminoplasty with selective fixation (LPSF) versus laminectomy with fusion (LCF) in patients with multilevel cervical myelopathy accompanied by segmental instability. Methods A case-control study was conducted by reviewing data from 63 patients who underwent LPSF (n = 30) or LCF (n = 33). Cervical alignment, range of motion (ROM), neurologic status and axial symptom severity pre-operation, 3-days after operation, and at the final follow-up (minimum 24 months) were measured and compared between groups. Results Postoperation, patients in the LPSF group lost 31.1 ± 17.3 % of cervical lordosis and 43.2 ± 10.9 % cervical ROM while patients in the LCF group lost 5.7 ± 8.2 % and 67.9 ± 15.5 %, respectively. Both LPSF and LCF groups significantly improved neurologic status and axial symptom severity at the final follow-up with similar between-group results(P > 0.05). Blood loss, operation time, hospital stay, and medical cost in the LPSF group were significantly less than in the LCF group(P < 0.05). Conclusions In 2 years of clinical observation, LPSF was effective in maintaining the stability of the cervical spine with less sacrifice of mobility and surgical trauma for multilevel myelopathy with segmental instability compared to LCF.