The authors measured the average diameter of bilateral superior ophthalmic veins (SOV) in 13 patients with spontaneous intracranial hypotension (SIH) on contrast-enhanced, coronal, T1-weighted MRI. Compared with sex- and age-matched neurology inpatients with normal CSF pressure, the SIH group had a smaller SOV diameter (0.90 vs 1.85 mm, p < 0.001), which partly reversed after treatment (1.09 vs 0.90 mm, p = 0.045, n = 7). Collapsed SOV might provide an additional MRI finding for SIH.