Cerebral amyloid angiopathy-related inflammation (CAA-ri) is a rare autoimmune encephalopathy of aging caused by an autoantibody immune response against Aβ protein deposited in the brain of older adults affected by cerebral amyloid angiopathy (CAA) and Alzheimer’s disease pathology. Its most common clinical manifestations are (sub)acute-onset cognitive and behavioral abnormalities, focal deficits, seizures, and headaches. Brain magnetic resonance imaging shows characteristic extensive and confluent white matter hyperintensities and CAA features. The response to immunosuppressive treatment is generally good. Here, we report the case of a 62-year-old patient with CAA-ri confirmed on biopsy, who had previously repeatedly received chemotherapy for multiple cancers. We summarize his clinical data, neuroradiological features, and therapeutic response and comment on the potential mechanisms connecting multiple cancers and chemotherapies with CAA-ri.