Provided are a variable focal length imaging lens, an optical apparatus having the imaging lens and a method for adjusting the imaging lens, whereby it is possible to achieve satisfactory optical performance and reduce a cost. The imaging lens comprises, in order from an object side, a first lens group G1 having negative refractive power and a second lens group G2 having positive refractive power. A focal length of the imaging lens is varied by changing an air space between the first lens group and the second lens group. The imaging lens further comprises an adjustment mechanism 20, 30 which performs a position adjustment for making shift decentering or tilt decentering of a whole or a partial lens group of the first lens group and a partial lens group of the second lens group, after assembling the first lens group and the second lens group.
