In minimally invasive surgery (MIS) the 3D perception and hand-eye coordination is reduced. A high degree of sensory-motor skills is required by the surgeon to mediate action and perception. The incorporation of robotic assistants is capable of integrating the required egocentric information to aid the surgeon providing a sense of presence. In this work we propose a robotic vision system as a tool to locate surgical instruments with respect to the surgeon. It estimates the absolute position of the port of entry, in which surgical instruments are inserted to access the patient body. The proposed algorithm shows that it is possible to estimate the orientation of the instruments with respect to the laparoscopic camera applying determined movements through the robotic assistant.