The invention relates to a device for the ultrasound testing of hot rolling material during the rolling procedure in one of a plurality of rolling stands in a rolling train which are arranged one behind the other, comprising at least two rolls which leave a roll gap between them, there being associated with the rolls ultrasound testing heads which are arranged such that parts of the roll body itself serve as the path along which the ultrasound waves pass on their way to the rolling material to be tested in the roll gap, which is characterised in that the rolls provided with the ultrasound testing heads are adjustable, have a straight transverse profile and a diameter which is a multiple of the width of the roll gap, with the result that a large rolling angle (α) is provided, and these rolls are arranged in one of the first rolling stands of the rolling train.