Food defense is the effort to protect food from causing harm to the consumer, including security procedures to mitigate intentional acts of adulteration. To assure entry in new markets, food companies need to develop and implement food defense strategies through third-party certification. Although there are some programs designed to assist food business operators in creating effective food defense strategies, this is still not regarded as a priority by food companies. As a first aim of this work, a first-party audit of two meat-producing industries was performed to verify the implementation of food defense requirements. The second purpose of the work was to compare vulnerabilities identified in those two food industries with the ones detected in other previously certified food units in Portugal. For such, a food defense requirements checklist was prepared for the audit and a private certification database was consulted to compare audit results with those from other food business operators certified by at least one international food defense standard. Audit results revealed that both industries were above 50% in overall compliance regarding food defense requirements; still the main vulnerabilities were related to the lack of a food defense plan, the failure to identify critical areas, ineffective warning systems and no training in food defense. Similar vulnerabilities were detected in other certified national food business operators, leading to the conclusion that implementation of food defense requirements seems to be underestimated. As an intervention strategy proposal, food defense training would be of upmost importance to get staff and managers acquainted with the concept.