To provide a method for stably producing a heat developable photosensitive material free from unevenness in coating while preventing a considerable change of the performance of the photosensitive material due to a stagnant coating fluid containing an organic silver salt and a reducing agent and a method for stably producing fine organic silver salt grains.

When a heat developable photographic sensitive material containing an organic silver salt, photosensitive silver halide grains and a reducing agent on the substrate is produced, at least one reducing agent is added to a coating fluid for a layer on the silver halide grain side and the top of the substrate is coated with the coating fluid within 1 hr after the addition. Fine organic silver salt grains are produced by carrying out grain growth while extracting a salt-containing aqueous solution from a reactant solution by ultrafiltration.