Hospitalized patients with chronic brain syndrome, whether associated with senile brain disease or cerebral arteriosclerosis, are especially subject to adverse side effects from phenothiazine derivatives. Previous favorable experiences with deanol acetamidobenzoate suggested a trial in managing the functional overlay of these disorders in patients presenting difficult ward problems. Fourteen subjects were treated over an average period of 2 weeks, most of them receiving oral doses of 100 mg. q.i.d.; several highly agitated patients were given intramuscular injections (60 mg. q.i.d.). A gratifying rate of success was achieved in spite of the generally unfavorable prognosis in cases of severe brain damage. More than half (53.8%) of the patients responded to deanol acetamidobenzoate with increased alertness and greater cooperation, thus requiring less nursing care. Side effects were minimal. The most outstanding successes were in agitated patients with suicidal tendencies. Until further investigations point the way to selecting patients predisposed to respond to treatment, an indiscriminate trial in all cases of chronic brain syndrome is eminently worthwhile.