The current literature shows mixed results regarding whether the perception of facial attractiveness is automatic, i.e. that it operates independently from attentional resources. We argue that an evolutionary perspective on mating strategies provides a comprehensive account of the findings. In two studies, we used the locus-of-slack logic in a psychological refractory period paradigm. Task 1 was a speeded judgment of tone pitch (low vs. high), and Task 2 was a speeded judgment of whether a face was attractive or unattractive on two difficulty levels. Male and female participants judged the attractiveness of opposite-sex faces (Study 1, n = 73) or same-sex faces (Study 2, n = 94) in this paradigm. Results indicate that men do not need attentional resources when processing female faces (Study 1), but require attentional resources when processing same-sex faces (Study 2). In contrast, women need attentional resources to process the attractiveness of opposite as well as same-sex faces.