A zoom lens includes a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens group having a positive refractive power or a negative refractive power. The lens groups are arranged in order from the object side toward the image side. The focal lengths of the system at a wide angle end and a telephoto end, the focal lengths of the first and second lens groups, the distance between the position of the first lens group, the position being closest to the object side upon zooming, and the position of the first lens group at the wide angle end, and the difference between the largest distance between the first and second lens groups upon zooming and the distance between the first and second lens groups at the wide angle end are determined.