Disclosed herein is a method for measuring the local stiffness index of the wall of a conducting artery carrying the blood of a patient. The method includes a step of measuring, at a single measurement point, the electric impedance variation of a volume of the blood flowing in a segment of the artery a step of determining a first intermediate index representative of a resistive characteristic involved in the stiffening of the wall, and a second intermediate index representative of a capacitive characteristic involved in the stiffening of the wall, the first and second intermediate indices being obtained from the measure of the electric impedance variation and a step of determining the local stiffness index based on the first and second intermediate indices.