The relationship of P3 latency of the event-related potential (ERP) to psychometric performance was investigated in 41 subjects who ranged in age from 20 to 88 years. P3 responses were recorded from subjects using an auditory oddball paradigm with and without task-demands. Subjects also received psychometric tests of verbal performance, visuospatial performance, concentration, and immediate, recent and remote memory. Factor analysis was used to reduce the set of psychometric measures to four factors (Verbal learning, general intelligence, narrative recall/fluency, and concentration). Both passive and active P3 latency showed a linear increase with age. Age was inversely correlated with verbal learning performance. After accounting for the influence of age, passive P3 latency correlated with the psychometric factor associated with narrative recall and verbal fluency. Active P3 latency was correlated with factors reflecting general intelligence and concentration. These findings suggest that cognitive processing speed contributes to psychometric performance in adults. The psychological or biological basis for this relationship remains to be identified.