Individuals with intellectual disabilities who exhibit psychotic verbal behavior are at increased risk for hospitalization and dependence on external support. Traditionally, medication is the clinical treatment of choice for this behavior. This article selectively reviews the existing literature within the field of behavior analysis on reducing psychotic verbal behavior in adults with intellectual disabilities. Both contingency-based and function-based treatments were effective. There was evidence that differential reinforcement, noncontingent reinforcement, and response-cost procedures were effective. The implications for future treatment and research on delusional verbal behavior are discussed.