Primates rely on visual attention to gather knowledge about their environment. The ability to recognize such knowledge-acquisition activity in another may demonstrate one aspect of Theory of Mind. Using a series of experiments in which chimpanzees were presented with a choice between an experimenter whose visual attention was available and another whose vision was occluded, we asked whether chimpanzees understood the relationship between visual attention and knowledge states. The animals showed sophisticated understanding of attention from the first presentation of each task. Under more complex experimental conditions, the subjects had more difficulty with species-typical processing of attentional cues and those likely to be learned during human contact. We discuss the results with respect to the comparative impact of enculturation on chimpanzees.