The plasma cholesterol levels of 279 students were measured and related to decision and movement times in choice reaction time tasks with one, two, four, and eight lamps.In female subjects, low plasma cholesterol levels were associated with slower movement times and, when responding to one or two lamps, slower decision times. In male subjects, there was a nonlinear relationship between cholesterol level and decision times. Because these data are correlational in nature, it is not possible to assume a causal relationship between cholesterol levels and speed of mental processing. The literature, however, supports the suggestion that further work should consider the possibility of a causal relationship.