Microbial investigation was carried out on 60 samples of frozen chilled foods retailed in Osaka City from August to November in 1998. The data was evaluated by comparing with the data of a standard inspection of frozen foods retailed in the city from 1994 to 1997. As a result, heated products before freezing except for cabbage rolls were not bacterially contaminated like frozen foods. In contrast, cabbage rolls were heavily contaminated because these were repacked or unpacked at stores before selling. On the other hand, unheated products were more contaminated than frozen foods. The result showed two important points to keep frozen chlled foods sanitary. First, heated products before freezing should be packed sanitarily and be well kept before selling. Second, unheated products before freezing should be made of sanitary materials; furthermore, they should be labeled as frozen foods and treated in accordance with the standard of the food sanitation law.