In order to determine whether changes in serum amylase are age- or sex-dependent, we evaluated age- and sex-stratified serum amylase values in subjects who were proven to be healthy by a precise preventive health examination. Results showed that serum amylase increased as age progressed, except in the 0- to 29-yr-old female group. Mean serum amylase was higher in females than in males. A previous study indicated that the etiology of the increase in amylase in elderly persons is due to a progressive decline in renal function with aging. The etiology of the sex difference, especially in the younger generation, requires further investigation. We should pay attention to the factor of age when we evaluate serum amylase.