At least one exemplary embodiment is directed to a zoom lens which includes, in order from an object side to an image side, a first lens unit, which can have a negative refractive power; a second lens unit, which can have a positive refractive power; and a third lens unit, which can have a negative refractive power. The second and third lens units can move in zooming. The first, second, and, third lens units can satisfy the following conditions: 1.2<|.phi.1/.phi.T|<2 0.9<.phi.2/.phi.T<2.2 0.75<.phi.3/.phi.1<1.2 wherein .phi.1, .phi.2, and .phi.3 are the refractive powers of the first, second, and third lens units, respectively, and .phi.T is the refractive power of the zoom lens at a telephoto end.