Compliance, or elasticity is present in many mechatronic system, e.g. when the transmission of a movement is done using steel cables, belts or elasti shafts. Also, compliance can be present in some gearboxes, typically the harmonic drivers, and in the links of a mecahanical structure, e.g. a robot. This elasticity always limits the performances of the system and the issue of its reduction or compensation is of prime importance. In a mechatronic system, this compensation can also be done electronically in a cheaper way. In thi paper, the basic principle of the compliance compensation is presented. Depending on the application and on the sensor locations, various strategies can be used. the theoricl devlopment are supported by two real application examples, i.e. the wrist stiffening of a bilateral Master-Slave force reflecting servomanipulator and the stiffening of the actuators of a big robotic transporter.