The present investigation examined a behavior-analytic clinical treatment package designed to reduce the pathological gambling of 3 individuals with acquired brain injury. A prior history of pathological gambling of each patient was assessed via caregiver report, psychological testing, and direct observation of gambling behavior. Using an 8-week one-on-one client-patient format, a treatment program was developed in which the patient learned about the antecedents, consequences, and motivating operations that controlled the emission of gambling behavior. Data were collected on both self-report of gambling urges and behavior following therapy and during in situ gambling opportunities. The therapy program reduced urges to gamble and actual gambling for all patients. The potential of behavior-analytic therapy for reducing the pathological gambling of patients with and without brain injury is discussed.