The fate of bacteria contained in food during freezing, storage, and thawing is usually one that is detrimental. However, many microorganisms considered to have been killed by such treatments actually are only injured. Their viability can be determined by allowing the injury to repair in a non-selective medium before testing for their presence on selective media. Injured cells of pathogens have been found to be as pathogenic as uninjured ones; injured spoilage microorganisms can cause spoilage if permitted to repair and grow. Injured microorganisms and their potential importance in food safety and shelf-life constitute and important problem for the frozed food industry as well as the food sanitarian.