A zoom lens of five group construction utilizing an inner focus system. The zoom lens includes a first lens group G1 having a positive refracting power, a second lens group G2 having a negative refracting power, a third lens group G3 having a negative refracting power, a fourth lens group G4 having a positive refracting power and a fifth lens group G5 having a negative refracting power, which are arranged in this order from an object side, and the distances among the respective lens groups are selectively varied to effect the desired zooming operation. During close-up photographing, the second lens group G2 is moved along an optical axis to effect the desired focusing.