Capecitabine, a precursor of 5-fluorouracil (5-FU), is a well-tolerated and safe chemotherapy that has been used to treat breast, pancreatic, and colorectal cancers. Albeit rare, both 5-FU and capecitbine have been reported to be associated with acute central nervous system toxicity, including cerebellar dysfunction, posterior reversible encephalopathy syndrome, and transient leukoencephalopathies. Here we present a case of 32-year-old female, demonstrating transient mutism related to capecitabine induced acute toxic leukoencephalopathy.