The present invention relates to a photothermographic material including, on a same surface of a support, a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent and a binder, wherein the photosensitive silver halide has a silver iodide content within a range from 40 to 100 mol %, and the material is thermally developed within a developing time of 12 seconds or less. The invention also relates to an image forming method using the photothermographic material.