A diaper or incontinence guard that includes a waist belt (1) and an absorbent unit (2) comprising a front part (3), a rear part (4) and an intermediate crotch part (5), and fastener devices (9-11 and 6-8 respectively) which are disposed at the front and the rear end of the absorbent unit and which can be fastened to said belt. According to the invention, each of the front and the rear ends of the absorbent unit (2) includes a respective central fastener device (10 and 7) that is located on the longitudinal symmetry axis (A-A) of the unit, and two lateral fastener devices (9, 11 and 6, 8 respectively) located on respective sides of the axis.