An exemplary zoom lens comprises, in order from an object side of the zoom lens, a first lens module having a negative refractive power, a second lens module having a positive refractive power and a third lens module having a positive refractive power. When the zoom lens is adjusted from wide-angle to telephoto, the first lens module remain fixed in place, the second group is moved toward the object side thereof along an optical axis so as to perform the zooming, while the third group is moved along the optical axis so as to compensate for any fluctuation of in position of an image on the image plane caused by the movement of the second lens module.