A method of rolling metal billets in a single pass comprises the steps of reducing a billet by workrolls and alternating each reduction cycle of the billet being worked with axial feed thereof through a step of rolling. As the billet is worked by the workrolls a transitional section is formed thereon as a deformation cone having a length along the axis of the billet substantially greater than the corresponding length of the deformation zone induced in the billet by each workroll at each given moment. The mill for carrying out this method comprises a frame having guides running in parallel with the axis of the billet being worked and mounting a roll housing geared to the mill drive to reciprocate the roll housing inside said guides in the course of rolling. The roll housing accommodates at least four variable-radius workrolls having their geometrical axes of rotation extended in one plane perpendicular to the axis of the billet being worked, the rotation of the workrolls about said axes being effected in the course of rolling positively and in synchronism with the reciprocations of the housing. The mill is also provided with a feeder for axially feeding the billet to the workrolls, mounted on the frame on the side of the billet entry to the workrolls and geared to the mill drive.