Disclosed is a surgical instrument with an articulated end-effector, such as a dissector, scissor or grasper, to enhance a surgeons performance during various surgical procedures. The longitudinal axis of the instrument is defined by a shaft, which may be inserted into a surgical incision or trocar in a body of a patient. The articulated end-effector is mounted on the distal extremity of the instrument shaft and comprises a plurality of links interconnected by a plurality of joints, whose movements are remotely actuated by the surgeons hands. This remote actuation is accomplished through mechanical transmission, mainly along flexible elements, which are able to deliver motion from a set of actuation elements, placed at a proximal extremity of the shaft, to the instruments articulated end-effector. The articulated end-effector further comprises one or more movement-amplification elements that amplify the movement transmitted by the flexible elements so that the movement of the proximal actuation elements can be minimized while the fatigue resistance of the instrument is maintained or increased. In addition, this invention can provide short distances between the articulations of the end-effector and guaranteed simplified maintenance procedures if some moving links of the end-effector have to be removed.