A method for ascertaining a side slip angle (beta) during a cornering maneuver of a motor vehicle, with the following input variables being recorded and linked to one another via a mathematical vehicle model having the assumptions of the linear single-track model: - a predetermined or measured position of the center of gravity (S) of the motor vehicle between a front axle and a rear axle of the motor vehicle , - the current vehicle speed (v) of the motor vehicle , - a current cornering movement variable (psipunkt, a) of the motor vehicle, - the current steering angle (delta) on the front axle, characterized in that, in the case of a stable cornering maneuver of the motor vehicle , the side slip angle (beta) is ascertained on the assumption that the difference between the side slip angle (beta) and the Ackermann side slip angle beta0 is proportional to the difference between the Ackermann angle (deltaA) and the steering angle (delta), the actual side slip angle (beta) being inferred from the relationship between the measured steering angle (delta) and the Ackermann angle (deltaA) via the proportionality relationship of the Ackermann side slip angle (beta0) theoretically present during slip-free travel on the same curve, and the side slip angle (beta) being ascertained as the difference between a first quotient of twice the rear axle distance (Lh) of the center of gravity (S) from the rear axle relative to the curve radius (R), which is taken into account as the ratio of the vehicle speed (v) to the cornering movement variable (psipunkt, a), and a second quotient of the product of the steering angle (delta) and the rear axle distance (Lh) relative to the wheelbase (L) between the front axle and the rear axle . - a predetermined or measured position of the center of gravity (S) of the motor vehicle between a front axle and a rear axle of the motor vehicle , - the current vehicle speed (v) of the motor vehicle , - a current cornering movement variable (psipunkt, a) of the motor vehicle, - the current steering angle (delta) on the front axle, characterized in that, in the case of a stable cornering maneuver of the motor vehicle , the side slip angle (beta) is ascertained on the assumption that the difference between the side slip angle (beta) and the Ackermann side slip angle beta0 is proportional to the difference between the Ackermann angle (deltaA) and the steering angle (delta), the actual side slip angle (beta) being inferred from the relationship between the measured steering angle (delta) and the Ackermann angle (deltaA) via the proportionality relationship of the Ackermann side slip angle (beta0) theoretically present during slip-free travel on the same curve, and the side slip angle (beta) being ascertained as the difference between a first quotient of twice the rear axle distance (Lh) of the center of gravity (S) from the rear axle relative to the curve radius (R), which is taken into account as the ratio of the vehicle speed (v) to the cornering movement variable (psipunkt, a), and a second quotient of the product of the steering angle (delta) and the rear axle distance (Lh) relative to the wheelbase (L) between the front axle and the rear axle . <EOS>