Posterior reversible encephalopathy syndrome is a rare neurological disorder, the diagnosis of which is based on the combination of clinical and radiological findings. It can be associated with many patient-related conditions such as autoimmune disorders or can be provoked by toxins or medication. We report the case of a 70-year-old patient, known for International Federation of Gynecology and Obstetrics stage IVB, high-grade serous ovarian carcinoma, who was diagnosed with a posterior reversible encephalopathy syndrome while on bevacizumab and olaparib maintenance treatment.