A zoom lens system includes, in order from an object side to an image side, first to fifth lens groups respectively having negative, positive, negative, positive, and positive refractive power. During zooming from a wide-angle end to a telephoto end, the second and third lens groups are moved independently toward the object side with spacing therebetween increased and that between the first and second lens groups decreased. The following condition is satisfied 1.05≦(fW·LW)/(fT·Y)≦1.53, wherein fW and fT are focal lengths of the zoom lens system at the wide-angle end and the telephoto end, Y represents a maximum diagonal length of an image plane, and LW represents a total length of the zoom lens system at the wide-angle end which is defined as a distance from the vertex of a first surface of the first lens on the object side to the image plane.