Abstract: A disposable diaper includes a liquid-impermeable topsheet, a liquid-permeable backsheet and an absorbent core therebetween. A pair of barrier cuffs which are elastically extendable in a longitudinal direction of the diaper are provided along transversely opposite side flaps of the diaper. Front and rear ends of the barrier cuffs are bonded to the diaper at longitudinally opposite ends thereof. Outer side edges of the barrier cuffs are bonded to outer edges of the flaps and inner side edges of the barrier cuffs are bonded to the flaps along lines defined between the outer side edges and transversely opposite side edges of the core. Each of the barrier cuffs has a dimension between the outer and inner side edges thereof selected to be larger than a dimension of the flap between the outer and inner side edges thereof.