A focussing and focal length adjusting device for an optical lens system in the camera head of an endoscope. This device includes a focussing device which has several piezoelectric bending actuators attached along and symmetrically to the optical axis of the focussing lens. The piezoelectric bending actuators are via in each case one joint member connected to a sleeve encompassing the focussing lens in a manner such that with voltage impingement bending movements carried out by the bending actuators are converted into a linear focussing movement for the focussing lens. Furthermore a zoom drive adjusting the focal length of a zoom lens system includes a stepper motor whose stepped rotation via a grooved roller and a pin linearly moved by the helical groove of this roller is converted into a linear movement of a zoom lens sleeve for the focal length adjustment. The activation of the stepper motor for the zoom operation, and the production of the focus adjusting signal for the piezoelectric actuators of the focussing device are effected during the vertical blanking interval of the video signal, this interval being extracted by an extraction circuit from the video signal and being led to a respective focussing circuit and a zoom control circuit in the form of a time window.