The occult neck metastasis rate of cT4aN0 glottic cancer was 33%. Ipsilateral levels IIA, III and VI should be dissected. Levels IIB and IV can be omitted to avoid complications. Abstract Objective The indication for elective neck dissection for patients with clinically T4aN0 (cT4aN0) glottic cancer is not established. The objective of this study was to evaluate the role of elective neck dissection for patients with cT4aN0 glottic cancer. Methods We assessed patients with cT4aN0 laryngeal squamous cell carcinoma who underwent total laryngectomy between 1998 and 2014 and conducted a retrospective analysis. We considered occult neck metastasis positive when confirmed by histological analysis. When patients with late neck metastases did not undergo therapeutic neck dissection, the presence of occult neck metastasis was judged on the basis of computed tomography. The validity of elective neck dissection for patients with cT4aN0 glottic cancer was assessed from comparisons the rates of occult neck metastases of supraglottic and subglottic cancers, which are generally recommended for elective neck dissection. The distribution of occult neck metastases in glottic cancer is described according to nodal levels. Results The rate of occult neck metastasis of cT4aN0 laryngeal cancer was 36% (14/39). There were no significant differences among the rates of glottic 7/21 (33%), supraglottic 3/8 (38%) and subglottic 4/10 (40%) cancers. Patients with glottic cancer did not have bilateral Level IIB and ipsilateral Level IV metastasis. One patient had contralateral Level IV metastasis. The metastases rates of ipsilateral Levels IIA, III, and VI were >10%. Conclusions We think that elective neck dissection is valid for cT4aN0 glottic cancer. Ipsilateral Levels IIA, III and VI should be dissected. The omission of neck dissection for bilateral Levels IIB and IV can be considered when there is a need to avoid complications.