The geometric and kinematic models of a new surgical hybrid robot used for camera and active instruments positioning are presented in this paper. The robot workspace is computed and illustrated following the singularities analysis. The robot structure consists of two modules: the PARAMIS robot, and the new serial positioning module. The serial positioning module is used to obtain a mechanically fixed remote center of motion (RCM), enabling the structure to manipulate also active instruments. The new robot provides the necessary motion control to respect the particularities and restrictions of surgical applications. The detailed workspace analysis demonstrates the importance of the relative positioning between the robot and the patient. A constructive solution of the new serial module, the numerical results and conclusions from the performed simulations are described.