SUMMARYExercise has been known to potentially affect food intake. Neuropeptide Y (NPY) is a 36 amino acid peptide and concentrated in the hypothalamus which is an appetite-regulating area. NPY is known to stimulate appetite and decrease energy expenditure. In the present study, the effect of treadmill running on the NPY expression in the hypothalamus of food-deprived rats was investigated using immunohistochemistry. Enhanced NPY expression in the paraventricular nucleus (PVN) and arcuate nucleus (ARN) was observed in the food-deprived rats. Treadmill exercise suppressed the enhancement of NPY expression in the PVN and ARN following food deprivation, but this suppressive effect was not affected by exercise intensity. Based on the present results, it can be suggested that treadmill exercise is effective in limiting the enhancement of NPY expression following food-deprived conditions.