The purpose of this study was to decide whether the P300 from an auditory three-stimuli oddball task is more sensitive to aging than the P300 from a two-stimuli task, and to investigate the relationship between neuropsychological tests and the different ways of eliciting the P300. Thirty-one adults (21.8-94.7 years) completed five neuropsychological tests and two ERP tasks. The way P300 was elicited did not influence its relationship to aging or neuropsychological scores, and the correlations between the two paradigms were strong for amplitude, but rather weak for latency. The main conclusion is that the P300 from an auditory three-stimulus paradigm is sensitive to aging and neuropsychologically valid.