The paper presents a new design of a stereo endoscope for minimally invasive surgery with: cameras positioned at the tip of the instrument (inside the patient), angle of convergence of the optical axes of the cameras variable continuously, and a foldable mechanism reducing the outer diameter of the endoscope to almost the diameter of the single camera in order to reduce the size of the insertion port. After the insertion the endoscope is deployed and the two cameras move side by side. A very simple compliant mechanism is used to drive the deployment and the adjustment of the convergence angle.