Abstract: An underpad for use in absorbing waste products of an incontinent person reclining on a bed mattress comprises a liquid resistent backing having a central portion straddled by two opposite end seams. Liquid absorbent batting is mounted to the backing central portion. The underpad also has a pair of elastic straps of lengths sufficient to be fastened to opposite backing end seams and drawn tautly in generally mutually parallel relation with each other beneath the mattress with the backing placed atop the mattress. Fastening means are also included for fastening the ends of the straps to the backing opposite side portions.