Provided is an optical observation system that is provided with a portable device, which is secured to an examination subject A and is moved together with the movement of the examination subject, and an external device disposed away from the examination subject, wherein the portable device is provided with a light source an illumination optical system radiates light coming from the light source onto an observation target site in the examination subject a detection optical system optically guides light coming from the observation target site a photodetector detects the light optically guided thereto by the detection optical system and converts the light to an electrical signal and a transmitter wirelessly transmits the electrical signal output from the photodetector and the external device is provided with a receiver receives the electrical signal transmitted from the portable device and a signal processor processes the electrical signal received by the receiver.
