The ability to discriminate facial expressions of emotion is important for human communication and interaction. When this ability develops is largely unknown, with the origins believed to lie in infancy. Behavioural and brain-based evidence suggests that infants are capable of differentiating positive and negative facial expressions (i.e., sad vs. happy, surprised vs. angry), however there is little research examining whether infants can make more fine-grained discriminations among negative facial expressions (e.g., fearful vs. angry). In the present paper, two experiments use a novel technique known as Fast Periodic Visual Stimulation (FPVS) to assess discrimination of facial expressions by adults (n = 33) and 7-month-old infants (n = 33). Adults discriminated facial expressions, but 7-month-old infants did not. Reasons why infants did not show a discrimination response are explored and the potential benefits of FPVS are discussed.