Behavioral and electrophysiological responses were monitored to 80 controlled sets of emotionally positive, negative, and neutral words presented randomly in a lexical decision paradigm. Half of the words were low frequency and half were high frequency. Behavioral results showed significant effects of frequency and emotion as well as an interaction. Prior research has demonstrated sensitivity to lexical processing in the N1 component of the event-related brain potential (ERP). In this study, the N1 (135-180 ms) showed a significant emotion by frequency interaction. The P1 window (80-120 ms) preceding the N1 as well as post-N1 time windows, including the Early Posterior Negativity (200-300 ms) and P300 (300-450 ms), were examined. The ERP data suggest an early identification of the emotional tone of words leading to differential processing. Specifically, high frequency negative words seem to attract additional cognitive resources. The overall pattern of results is consistent with a time line of word recognition in which semantic analysis, including the evaluation of emotional quality, occurs at an early, lexical stage of processing.