Deaf and hard-of-hearing persons are at risk for experiencing traumatic events and such experiences are associated with symptoms of mental disorder. We investigated the prevalence of traumatic events and subsequent traumatization in adults referred to specialized psychiatric outpatient units for deaf and hard-of-hearing patients. Sixty-two patients were diagnosed with mental disorders and assessed for potential traumatic experiences in their preferred language and mode of communication using instruments translated into Norwegian Sign Language. All patients reported traumatic events, with a mean of 6.2 different types; 85% reported subsequent traumatization not significantly associated with either residential school setting or communicative competence of childhood caregivers. Traumatization patterns in both sexes were similar to those in hearing clinical samples. Findings indicate that psychiatric intake interviews should routinely assess potentially traumatic events and their impacts, and that mental health professionals working with deaf and hard-of-hearing patients should be able to treat trauma-related disorders.