Background: Elevated serum retinol, CSF retinol, and serum retinol binding protein (RBP) levels have been found in some patients with idiopathic intracranial hypertension (IIH), but serum and CSF retinol levels have not been studied in matched serum and CSF samples in patients with IIH.Objective: To determine whether serum and CSF vitamin A concentrations are associated with IIH.Methods: The serum and CSF retinol concentrations were prospectively assessed in 20 patients with IIH and 20 control subjects. Results: CSF retinol concentration was higher in the patient group (median 575.91 nM) vs the control group (median 63.35 nM) (p < 0.05). There was no difference in serum retinol levels between control subjects (median 896.51 nM) and patients (median 1,002.62 nM) (p = 0.10). There was an association between higher vitamin A levels (> 250 nM) and IIH (p = 0.039). There was a correlation between CSF and serum retinol levels in patients (r = 0.82) and control subjects (r = 0.66).Conclusion: Elevated CSF retinol concentration is associated with idiopathic intracranial hypertension (IIH), but serum retinol level is not associated with IIH.