In this paper the concept of a serial-parallel macro-milli manipulator is presented for medical applications by investigating the feasibility of combining two different robotic structures into one system. The combination of the two structures can be used as a redundant system in which stiffness, singularity and accuracy can be optimized as related to workspace demands and restrictions that are required for a priori selected medical applications. A case study has been experienced at LARM (Laboratory of Robotics and Mechatronics) at the University of Cassino through a new system composed of a commercial Adept COBRA and CaPaMan2bis (Cassino Parallel Manipulator 2bis). The performance of this system is compared with a previous serial-parallel macro-milli robotic system also developed at LARM in Cassino. Experimental tests have been carried out in order to characterize the proposed systems.