Attention is regulated by three independent but interacting networks, that is, alerting, comprising phasic alertness and vigilance, orienting, and executive control. Previous studies analyzing event-related potentials (ERPs) associated with attentional networks have focused on phasic alertness, orienting, and executive control, without an independent measure of vigilance. ERPs associated with vigilance have been instead measured in separate studies and via different tasks. The present study aimed to differentiate ERPs associated with attentional networks by simultaneously measuring vigilance along with phasic alertness, orienting, and executive control. Forty participants (34 women, age: M = 25.96; SD = 4.96) completed two sessions wherein the electroencephalogram was recorded while they completed the Attentional Networks Test for Interactions and Vigilance—executive and arousal components, a task that measures phasic alertness, orienting, and executive control along with executive (i.e., detection of infrequent critical signals) and arousal (i.e., sustaining a fast reaction to environmental stimuli) vigilance. ERPs previously associated with attentional networks were replicated here: (a) N1, P2, and contingent negative variation for phasic alertness; (b) P1, N1, and P3 for orienting; and (c) N2 and slow positivity for executive control. Importantly, different ERPs were associated with vigilance: while the executive vigilance decrement was associated with an increase in P3 and slow positivity across time-on-task, arousal vigilance loss was associated with reduced N1 and P2 amplitude. The present study shows that attentional networks can be described by different ERPs simultaneously observed in a single session, including independent measures of executive and arousal vigilance on its assessment.