A shock absorber with a hydrostopper is provided. The hydrostopper includes a stopper piston that is relatively displaceable along a rod portion of a piston and partitions one cylinder chamber into an upper chamber and a lower chamber, and a compression coil spring that biases the stopper piston against a stopper disc fixed to the rod portion in the lower chamber. The stopper piston has an orifice passage connecting the upper and lower chambers. The hydrostopper includes an elastic disk functioning as an elastically deformable member that increases an amount of elastic deformation to increase an amount of reduction of an effective passage cross-sectional area of the orifice passage as a differential pressure between pressures in the upper and lower chambers is larger when the pressure in the upper chamber is higher than the pressure in the lower chamber.