Abstract: The paper describes the realization of a force-torque sensor to be employed for applications of medical robotics. The sensor was designed and built in the Mechatronics laboratory of the Dept. of Electrical, Management and Mechanical Engineering of the University of Udine. The aim of the sensor is to measure the values of the forces and torques applied by the external environment to the end effector of a robotic manipulator. This is of fundamental importance when interaction of the robot with the external world must be considered and gauged. In particular, the robot is intended to perform a surgical task, such as the perforation of vertebrae for insertion of peduncular screws. Such an operation is to be done by a master-slave robotic system, where the master robot is connected to the slave by means of a haptic interface. The master sends the command to the slave, which executes the task and feeds back to the master the information of the force and torque values obtained by measuring the interaction of the robotís end effector with the external world. In order to perform this measurement, an adequate sensor has been de-signed and built. The application of the sensor described in this paper are therefore very important in the medical robotics field, as well as in many other robotic applications.