Conclusion. Our results suggest that patients with migraine or tension-type headache have subclinical deviations of the subjective visual vertical, which may be associated with their subjective imbalance Objectives. Patients affected by migraine or tension-type headache often complain of unsteadiness. However, they rarely show a clinical significance in the objective examinations of their equilibrium. We investigated the equilibrium functions in patients affected by migraine or tension-type headache Subjects and methods. We investigated the neurotological findings of 17 patients with migraine, 20 patients with tension-type headaches, and 16 patients without headache. All patients in this study experienced vertigo or dizziness before they underwent the examination; however, they never had vertigo attacks for more than 1 month before the examination. All patients in this study were tested during headache-free intervals Results. There was no significant difference in the hearing levels of pure tone audiometry, the canal palsy percentage of bithermal caloric test, and the body sway in posturography among the three groups (p0.05, Mann-Whitney U test). The average values in absolute deviations of subjective visual vertical (SVV) in patients with tension-type headache (1.31.1) and patients with migraine (1.51.2) were significantly larger in comparison with those of patients without headache (0.60.4) (p0.05, Mann-Whitney U test). Intra-individual varaiances of the SVV in patients with primary headache were significantly larger than those in patients without headache (p0.05, Mann-Whitney U test).