Forty-two long-stay hospital patients with chronic schizophrenia were divided into age and sex-matched groups with and without temporal disorientation, and assessed for premorbid academic performance and past physical treatment. The schooling of schizophrenic patients who had cognitive impairment, as identified by gross temporal disorientation, did not differ from those who were cognitively intact. The groups did not differ in past history of ECT, insulin coma, neuroleptic treatment, or psychosurgery. Patients with age disorientation were on lower mean doses of neuroleptic or anticholinergic medication. Gross cognitive impairment thus appears to occur in the course of the disease and is not due to physical treatment.