A zoom lens system includes a negative first lens group, a positive second lens group and a positive third lens group, in that order from the object side. Upon zooming from the short to long focal length extremities, the distance between the first and second lens groups decreases, and the distance between the second and third lens groups increases. The first lens group includes a negative lens element and a positive lens element; and the second lens group includes a cemented lens including a positive lens element and a negative lens element, and a negative lens element, in that order from the object side. The following conditions are satisfied by the zoom lens system: 1.8