A method of adjusting the stroke of a press brake having a movable beam (1) supporting a punch (2), a fixed beam (3) supporting a die (4), means of displacing (5, 5′) the movable beam with respect to the fixed beam, said displacement means resting on side frames (6, 6′) immovably attached to the fixed beam, linear encoders (9, 9′) for measuring the displacement of the movable beam with respect to the side frames, at least one sensor (8, 8′) measuring a physical parameter (p) varying with the force exerted by said punch on a metal sheet placed on said die, and an electronic device for controlling (7) the bending movement controlling the speed of said displacement movement between top dead center and bottom dead center (BDC), provided with a calculation means for correcting the value of said bottom dead center depending on the measurement of said displacement and said physical parameter. The difference in thickness between the actual thickness of the metal sheet and the reference value (e) of the thickness of the metal sheet is measured by comparing the actual position of said displacement at which there occurs a predetermined variation &Dgr;p of said physical parameter (p) with the theoretical position of said displacement where this variation &Dgr;p should occur, and the electronic control device (7) calculates a correction of bottom dead center by taking account of said difference in thickness.