A connector clip for medical sensors, including a first main body having two main tip contacts in electrical contact with electrical wires connectable to an instrument and a second main body mounted on the first main body and movable with respect to the first main body between an open position and a closed position. Two auxiliary tip contacts and an electric/electronic circuit provided with two connecting leads each electrically connected to one of the two auxiliary tip contacts are positioned in first or second main body. When a disposable sensor tab is correctly located and clamped each of two contacts is in contact with one of the main tip contacts and one of the auxiliary tip contacts and the electric circuit is connected in parallel with an electrical circuit defined by the sensor