Objective: To investigate the association of diabetes mellitus (DM) with vertigo outcome in patients with vestibular migraine (VM). Methods: Two hundred and thirty-four patients with VM were consecutively enrolled between October 2018 and January 2020 in a tertiary teaching medical center. Multivariable linear regression model and stratified analyses were used to explore the relationship between diabetes and vertigo outcome, which was measured by the visual analogue scale (VAS). Results: Patients with diabetes were more likely to have poorer sleep quality and more severe vertigo symptoms measured by VAS at the follow-up than those without diabetes. After adjusting for potential confounders, presence of diabetes was significantly linked with poorer final vertigo VAS score (beta, 95 % confidence interval [CI]: 1.0 [0.1, 2.0]). This association was only significant for female patients with VM (beta, 95%CI: 1.2 [0.2, 2.3], p = 0.0244). Conclusions: Presence of diabetes was independently and inversely corrected with the vertigo outcome in women with VM. Our findings suggest that diabetes is likely a negative prognosticator of vertigo outcome in VM.