A photothermographic imaging material including a support having thereon an image forming layer containing light-insensitive organic silver salt grains, photosensitive silver halide grains, a reducing agent for silver ions and a binder, wherein: (i) each of the photosensitive silver halide grains produces a larger number of latent images in a surface portion of the grain than in an inner portion of the grain by exposure to light; (ii) each of the photosensitive silver halide grains produces a larger number of latent images in the inner portion of the grain than in the surface portion of the grain after being subjected to a thermal development; (iii) a surface photographic speed of each of the photosensitive silver halide grains decreases after being subjected to the thermal development; and (iv) the photothermographic imaging material contains a reducible silver salt compound represented by Formula (I) described in the specification.