Background: Older outpatient women with late-onset (LOS) schizophrenia can be distinguished from than women with early-onset (EOS) and men with EOS or LOS by having less severe negative symptoms and more severe tardive dyskinesia. There are several explanations for these gender by age of onset results: 1) Women with LOS have a different clinical presentation of schizophrenia; 2) Women with LOS have a different form of schizophrenia; 3) There may be an “estrogen-related” form of schizophrenia than is most apparent in women who develop schizophrenia after the age 45. Aims: To investigate the neuropsychological functioning in women with LOS. Methods: Neuropsychological functioning in 254 outpatients with the DSM-IV diagnosis of schizophrenia or schizoaffective disorder was assessed using 2x2 (gender by age of onset) analysis of variance for T-scores for each of the following ability areas: Verbal, Psychomotor, Abstraction/Flexibility, Attention, Learning/Incidental Memory, Retention, and Motor. Results: The four groups did not differ with respect to education or total score on the Brief Psychiatric Rating Scale. Patients with EOS had significantly more severe impairments of Learning/Incidental Memory (F= 13.28, P=0.001) and tended to have worse scores on Abstraction/Flexibility (F=3.25, P=0.07). There were no significant gender differences. Women with LOS performed significantly worse than women with EOS or men with LOS or EOS in the Motor domain (F=12.08, P=0.001), scoring in the mildly impaired range. Conclusion: Women with LOS did not demonstrate a differential impairment of neuropsychological functioning with the exception of having worse motor performance. This suggests that the underlying pathophysiology of schizophrenia in women with LOS is similar to that of women with EOS and men with EOS or LOS. The clinical presentation of schizophrenia is somewhat different in LOS women, however, the possibility of an “estrogen-related” variant cannot yet be ruled out. P60