Abstract: Pazopanib is an oral protein kinase inhibitor (PKI) that targets vascular endothelial growth factor (VEGF) receptors, fibroblastic growth factor receptors, platelet-derived growth factor receptors, and stem cell factor that inhibits VEGF-induced cellular proliferation. Pazopanib is approved for use in advanced renal cell carcinoma and subtypes of advanced soft-tissue sarcoma (Deguchi et al., 2018). Major adverse drug reactions of pazopanib include hyper- tension, high-grade hyponatremia and posterior reversible encepha- lopathy syndrome (PRES) (Berardi et al., 2016; Deguchi et al., 2018). In clinical trials, few investigations have been conducted to deter- mine the aetiology of PKI-associated hyponatremia, the mechanism remains therefore unknown. Only rare cases of PKI-induced syn- drome of inappropriate secretion of antidiuretic hormone (SIADH) (Largeau et al., 2019), and none with pazopanib, have been reported. PRES is a clinical and radiological entity where a bilateral white mat- ter oedema, occurring predominantly in the posterior occipital and parietal lobes, is associated with several neurologic symptoms. Inter- estingly, a recent review suggests that SIADH could be a symptom of PRES (Largeau et al., 2019). To our knowledge, this is the first case published where pazopanib-induced PRES occurs contemporane- ously with possible SIADH.