To provide a disposable diaper for pets having an excellent fit around the waist of the pet. A disposable diaper for pets, having: a rear-side waist area (130); a stomach-side waist area (110); a crotch area (120); an inside surface (100Z1); an outside surface (100Z2); an absorbent core (200); an area (200) not having the absorbent core arranged therein; an attachment section (300) provided in the stomach-side waist area (110) and having a prescribed length; a hook section provided in the attachment section (300); and an attachment area (900) provided on the outside surface (100Z2) of the rear-side waist area (130) and which receives the hook section of the attachment section (300). The attachment area (900) comprises a non-woven first attachment area (900A) arranged on the outside surface (100Z2) of a diaper main body section (140B) in an area (170) not having the absorbent core arranged therein, in at least the rear-side waist area (130).