Provided is a medical observation device including an imaging unit configured to capture an image of an object to be observed, and output a video signal, and a support unit configured with a plurality of arm units rotatably connected to each other via joint units, and configured to support the imaging unit. An actuator that applies driving force with respect to rotation about a rotational axis of at least one joint unit that defines an attitude of the imaging unit, among a plurality of the joint units that form the support unit, is provided. The at least one joint unit and the actuator are arranged separated from each other, and are connected together via a power transmission mechanism that transmits rotary movement between two rotational axes that are substantially orthogonal to each other.