A stabilizing system for a self-propelled working machine such as a telescopic handler or the like, comprising a plurality of stabilizer arms able to be placed on the ground so as to enable stabilization of said machine and further comprising: one or more measuring devices able to detect a pressure to which said arms are subjected and to produce pressure signals according to said detected pressure; at least one processing unit connected to said measuring devices and comprising a position module configured to determine, based on said pressure signals, whether the arms are placed on the ground; and scissor stabilizers that include two pairs of said arms for stabilization, each of which is rotatable and that include a plurality of actuators suitable for determining the rotation of respective stabilizer arms and the lifting of said machine ; wherein each stabilizer arm is telescopic and comprises at least one sleeve , in which an extractable element bearing a member for being placed on the ground, is slidably inserted substantially without any play, so as to enable extension or retraction of the arm ; wherein said scissor stabilizers are equipped with a support element , for each pair of arms , said support element being intended to be fixed to the working machine and to which the sleeve of each arm is connected by means of a first hinge , and wherein a hydraulic cylinder is comprised in each actuator, the cylinder being connected by means of a second hinge to said support element and, by means of a third hinge to the sleeve of a respective arm ; characterised in that at least one measuring device comprises a first extensometer pin included in said second hinge connecting a hydraulic cylinder and the support element . one or more measuring devices able to detect a pressure to which said arms are subjected and to produce pressure signals according to said detected pressure; at least one processing unit connected to said measuring devices and comprising a position module configured to determine, based on said pressure signals, whether the arms are placed on the ground; and scissor stabilizers that include two pairs of said arms for stabilization, each of which is rotatable and that include a plurality of actuators suitable for determining the rotation of respective stabilizer arms and the lifting of said machine ; wherein each stabilizer arm is telescopic and comprises at least one sleeve , in which an extractable element bearing a member for being placed on the ground, is slidably inserted substantially without any play, so as to enable extension or retraction of the arm ; wherein said scissor stabilizers are equipped with a support element , for each pair of arms , said support element being intended to be fixed to the working machine and to which the sleeve of each arm is connected by means of a first hinge , and wherein a hydraulic cylinder is comprised in each actuator, the cylinder being connected by means of a second hinge to said support element and, by means of a third hinge to the sleeve of a respective arm ; characterised in that at least one measuring device comprises a first extensometer pin included in said second hinge connecting a hydraulic cylinder and the support element . <EOS>