Chlorambucil is an alkylating agent commonly used in veterinary oncology for conditions including lymphoma. Chlorambucil neurotoxicity has been well recognized in human patients. Onsets of central nervous system signs, such as myoclonus, tremors, muscular twitching, agitation, and tonic-clonic seizures, have been reported in humans and laboratory animals treated with chlorambucil. This case of a cat with intestinal lymphoma represents the first veterinary patient reported to have chlorambucil-induced neurotoxicity. Neurotoxicity should be considered a potential side effect of chlorambucil therapy in veterinary patients.