Autism spectrum disorder (ASD) is characterized by a range of symptoms, including restrictive behaviors and deficient social skills. We investigated EEG correlates of social attention, face, and non-face perception by applying a continuous performance test (CPT) with two different sets of stimuli (letters and faces). The CPT required participants to respond to a specific target stimulus (e.g., "X") only when it followed a specific preceding stimulus (e.g., "O"). Event-related potential (ERP) components, including P100, N170, P200, N250, P300, and continuous negative variation (CNV), were analyzed in 19 young adults with ASD and 19 typically developed (TD) individuals that were matched for intelligence, age, and gender. TD participants had higher accuracies only for the target condition and regardless of stimulus type. No ERP differences between the two groups were found for the CPT with letter stimuli. By contrast, autistic individuals exhibited lower amplitudes of P300 and CNV during face CPT. Results suggest diminished allocation of attentional resources and response preparation towards socially relevant face stimuli.