An object is to provide a vibration reduction (VR) zoom lens system having high optical performance and compactness suitable for an SLR camera, a video camera and the like. The zoom lens system includes, in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having negative refractive power, and a fifth lens group having positive refractive power. All distances between adjacent lens groups are changed upon zooming from a wide-angle end state to a telephoto end state. The third lens group includes a plurality of lenses including a cemented lens constructed by a negative lens cemented with a positive lens. Only the cemented lens is used as a vibration reduction lens shifting substantially perpendicularly to the optical axis for correcting camera shake. Given conditional expressions are satisfied.