A photothermographic material comprising an image forming layer, on at least one side of a support, comprising at least a photosensitive silver halide, a non-photosensitive silver salt, a reducing agent, and a binder, wherein 50% by weight or more of the binder is formed by a linear polymer, and wherein a mean grain size (D0.5) of developed silver in an image portion having a density of 0.5 and a mean grain size (D3.0) of developed silver in an image portion having a density of 3.0 satisfy a relationship represented by the following equation (1): D0.5/D3.0≧1.1  Equation (1) A photothermographic material having a high image quality with high image density and excellent color tone of developed silver images is provided.