Posterior reversible encephalopathy syndrome (PRES) is a clinical syndrome of headache, altered mental status, and seizures with reversible mainly posterior leukoencephalopathy on neuroimaging. Precipitating factors for PRES are multifactorial and include autoregulatory failure due to changes in blood pressure, metabolic derangements, and cytotoxic medications. We report the second case of cyclophosphamide-induced PRES in a patient with anti-glomerular basement membrane (Anti-GBM) positive vasculitis. In the acute setting, PRES can be challenging to distinguish from cerebral venous sinus thrombosis or cerebral vasculitis based on clinical presentation. Neuroimaging with magnetic resonance imaging (MRI) of the brain along with a vessel imaging, can help reach the diagnosis.