Provided is an excrement disposal bag that is easy to handle and able to be produced at low cost. This excrement disposal bag comprises a first bag composed of water-soluble paper and a second bag, which is made of a synthetic resin, which is housed in the first bag, and which is provided with folded portions at both lateral sides thereof, the excrement disposal bag being characterized in that, in a state in which the folded portions of the second bag are unfolded outward so that the first bag and the second bag are both made to flatten out, the outer width of the second bag falls within a range of 1.02-1.2 times the inner width of the first bag, while the height of the second bag from an outer bottom edge to an opening edge falls within a range of 1.4-1.6 times the inner depth of the first bag.
