A variable-focal-length lens system includes first to fifth lens groups having positive, negative, positive, negative, and positive refractive powers, respectively, from the object side. As the lens-position state changes from wide-angle to telephoto, the air space between the first and second lens groups increases, the air space between the second and third lens groups decreases, the air space between the third and fourth lens groups changes, the air space between the fourth and fifth lens groups increases, the first lens group moves monotonously toward the object, the second lens group is fixed in the optical-axis direction, and the third and fourth lens groups move toward the object. Conditions 0.2