BACKGROUND: The cervicothoracic junction (CTJ) has often been identified as an area of biomechanical vulnerability; however, few studies have examined the relative merits of extending fusions across this area. In this study, we sought to investigate the tradeoffs involved in fusing across the CTJ in cases of elective posterior cervical laminectomy and fusion. METHODS: We conducted a single-institution retrospective cohort study of patients undergoing elective, multilevel, posterior cervical decompression and fusion for degenerative cervical stenosis. Data were collected on baseline clinical and radiographic variables as well any subsequent complications or reoperations. Outcomes measures were compared between those who received fusion stopping at C7 with those who received fusion crossing the CTJ, with multivariate logistic regression used to adjust for any known confounders. RESULTS: Patients whose fusion crossed the CTJ were found to have more levels fused (mean: 5.8 vs. 3.5 levels, P < 0.0001), longer surgical times (mean: 216 vs. 149 minutes, P < 0.0001), and higher estimated blood losses (mean: 475 vs. 116 mL, P < 0.0001) despite no significant differences in number of levels decompressed (mean: 4.2 vs. 4.3 levels, P = 0.63). The groups did not differ in overall reoperation rate (10.8% vs. 9.4%, P = 1.00), but crossing the CTJ was associated with a higher rate of wound dehiscence (7.8% vs. 0%, P = 0.03). This difference persisted in multivariate analysis (P < 0.001). CONCLUSIONS: Crossing the CTJ was associated with increased surgical time, estimated blood loss, and the rates of wound dehiscence. These tradeoffs should be considered in planning posterior cervical decompression and fusion procedures.