A method for evaluating the fit of a disposable diaper having a stretchable region in the waist-engirding section or the leg-engirding sections, said method being characterized in having an evaluation image acquisition step in which, when the disposable diaper is being worn, a terminal having a photographing function acquires, as an evaluation image, an image including at least part of the stretchable region, and an evaluation step in which the fit of the disposable diaper is evaluated on the basis of the degree of deformation in the evaluation image.