The necessity of routine carotid sheath removal during neck dissections for head and neck carcinomas, particularly in clinically N0 and N+ necks without extranodal extension (ENE), remains debatable. This prospective study aimed to document the incidence of pathological involvement of the carotid sheath in such cases. A total of 121 patients with oral squamous cell carcinoma underwent neck dissections with the carotid sheath left intact unless infiltration was suspected. Among these, only one patient (0.8%) exhibited carotid sheath involvement, while 120 (99.2%) did not. No regional recurrences were observed during a minimum follow up of six months. These findings suggest that routine resection of the carotid sheath is unnecessary during elective or therapeutic neck dissection for head and neck carcinomas, as it does not increase the risk of regional recurrence. Preserving the carotid sheath may therefore be a viable approach, potentially reducing surgical morbidity without compromising oncological outcomes. To the best of our knowledge, this study, which includes 121 patients and 145 necks, is the largest sample size to date to examine carotid sheath involvement in routine neck dissections.