Change blindness is the striking inability to detect seemingly obvious changes that occur between views of a scene. The current study assessed perceptual load as a factor that may affect change blindness for human faces. The study had participants (n=103) interact with a researcher in a testing room that imposed low or high perceptual load. Midway through the conversation, the researcher was replaced by another person. Thirty-nine percent of participants failed to detect the change. There was a significant effect of perceptual load, with greater change detection under low load (71%) than high load (52%). This research suggests that the perceptual load imposed by a task may have a significant effect on the likelihood of change blindness and ought to be considered in future research.