The conventional two-step desolvation method was modified for the fabrication of small gelatin nanoparticles (GNPs). The technique was based on the natural phenomenon where with decreasing temperature, the compression between the molecules of substances increases and the volume shrinks. The average size of the fabricated small GNPs was less than 100 nm and their gelatin properties (including non-cytotoxicity) were well maintained. The drug release profiles of the GNPs were confirmed, for which a simple mathematical model based on the conventional diffusion equation was proposed. There was a burst of drug release in the first 3 days, with different release profiles according to the concentration of model drugs loaded onto the GNPs. It was also demonstrated that the drug release profiles of the proposed mathematical model were consistent with the experimental results. Our work proposes that these small GNPs could be used as efficient small material delivery platforms for various biomedical (e.g., medical drugs) and agriculture (e.g., pesticides) applications.