The purpose of this study is to identify factors affecting the winning bid price of small and medium-sized buildings, one of the most popular types of real estate investment in Korea, with the winning bid price of small and medium-sized buildings as the dependent variable and auction characteristics, location characteristics, building characteristics, and regional characteristics as independent variables those are considered as common influential factors of small and medium-sized building auctions. The study collected case data from 315 auctions of neighborhood living facility buildings having nine floors or lower under Class 1 and Class 2 of the Building Code, which were auctioned at the Seoul District Court from 2013 to 2022. The results of the multiple regression analysis using the hedonic pricing model summarize the factors affecting the winning bid price of small and medium-sized buildings as follows. First, in terms of auction characteristics, the number of bidders variable shows a positive sign, while the number of failed auctions shows a negative influence. Second, in terms of location characteristics, the number of subway stations, daytime working population, and average income variables have positive effects. In contrast, the number of residential units has a negative effect. Third, in terms of building characteristics, the land area variable has a positive effect, while the usable area ratio, the floor, and the building coverage ratio have adverse effects. Fourth, in terms of regional characteristics, the CBD area variable was found to have a positive effect. These results can be used as a basis for the auction bidding factors of small and medium-sized buildings and can be used to make rational auction bidding decisions for small and medium-sized buildings.