This particular model number is 62% cotton/poly.  It is small enough for a younger boy, and stretchy enough to allow for a couple years growth.  There is little consistency among availability of Hanes brand as to cotton/poly ratio.  Most are too much cotton or too much poly.  These happen to be good blend of absobancy and stretch.  As long as this particular model number (361) is available, I will stick with 5 stars. There are other #'s I have given 1 and 2 stars.  It is unfortunate that buying this brand is hit and miss, so buyer be vigilant.