Antimicrobial activity of persimmon leaf tea methanol extracts on Klebsiella pneumoniae and Staphylococcus aureus was examined through paper disk diffusion bioassay. K. pneumoniae and S. aureus showed 87.64 and 99.35% growth inhibitions by addition of steamed tea methanol extracts (10 mg/ml), respectively. The number of microorganisms in rice cakes was significantly reduced when leaf tea powder was added during production of rice cakes. Addition of 1% steamed leaf teas to rice cakes decreased the number of microorganisms by over 50%, and over 70% reduction was observed when final 2% (dried weight w/w) steamed leaf tea was added, whereas no significant effect was observed over 2%. These results indicate that different microorganisms were detected from persimmon leaf and rice cake, and persimmon leaf can inhibit normal microbial growth in rice cake.