In the 30 year time period that microwave ovens have been used in households, several studies have examined variables that influence temperatures and bacterial destruction achieved in foods heated by microwave energy. Factors of primary importance include both physical and chemical (product mass, density, specific heat, ionic content, dielectric properties) parameters. The majority of evidence indicates that microwaves inactivate microbes by thermal effects alone. Concern about the safety of microwave-heated foods has arisen because of the abbreviated thermal treatment that microwave heating affords, the potential for temperature abuse of microwavable products, and the risk of pathogen survival in foodservice cook/chill foods. Foodborne pathogens such as Listeria monocytogenes , Staphylococcus aureus and Salmonella spp. have been the focus of most studies of microwavable food safety, primarily because of their ubiquitous nature and prevalence in causing illness. The practical implications of the findings of both basic and applied studies of bacterial destruction within microwave-heated products are examined.