Cedar shoe trees are used to keep shoes from shrinking and losing their shape. When the same cedar shoe trees are used by different shoe wearers, there is a chance of transmission of disease-causing microorganisms between people. This study was conducted to determine whether or not transmission of disease-causing microorganisms via cedar shoe trees occurs, what kinds of microorganisms can be transmitted, and how many organisms can be transmitted. In this study, both bacteria and bacterial spores were transmitted, while fungi were not; however, only several hundred to several thousand pathogenic bacteria were transmitted between any two shoes.