The association of P300 components with age, illness duration and gender were examined in schizophrenia patients and whether such variables indicate a progressive course. A total of 60 patients with schizophrenia and 70 healthy controls were studied utilizing standard auditory oddball tasks. Both healthy and schizophrenia groups had a significant positive correlation between age and P300 latency. There was also a significant positive correlation between illness duration and P300 latency in the schizophrenia group. The prolonged latency of P300, associated with age or illness duration, was more prominent in male than female schizophrenia subjects. These findings suggest gender differences in disease progression in schizophrenia.