The invention provides a zoom lens that comprises a reduced number of lens elements, is compact and simplified, and has high image-formation capability, thereby achieving thorough size reductions in video cameras or digital cameras, and an electronic imaging system using the same. The zoom lens comprises, in order from its object side, a lens group A (G1) having negative refracting power and a lens group B (G2) having positive refracting power. For zooming, the lens groups A and B are designed to move. The lens group B is composed of three meniscus lenses, each convex on its object side.