This case report demonstrates challenges diagnosing psychosis in language dysfluent deaf patients. Treatment of a 34-year-old deaf man on an inpatient psychiatric unit is described. He had a history of physical aggression and possible symptoms of paranoia and thought disorganization, in addition to learning difficulties and minimal language skills. The patient was placed on a combined hearing/deaf inpatient unit, received specialized programming for deaf patients and was prescribed risperidone and divalproex sodium to treat his aggressive behavior and possible psychosis. Uncertainty if the patient were having psychotic symptoms remained throughout his hospitalization, although he improved behaviorally and was discharged after 13 months of treatment. The patient's pre-existing language deficits made accurate diagnosis and appropriate treatment challenging. It is important for clinicians to be aware of the frequency of language dysfluency in the deaf inpatient population and have a strategy for evaluating and treating this complex subgroup of deaf people.