PurposeA food safety management system (FSMS) is a dynamic resource with the potential to generate competitive advantages, whose implementation may be certified according to internationally recognised standards such as the Brand Reputation Compliance Global Standards (BRCGS). This research sets out to discover why companies implement these systems and the influence each one of them exerts.Design/methodology/approachData have been gathered via a questionnaire administered in Spanish-speaking countries on both sides of the Atlantic, compiling a sample of 574 companies certified to BRCGS. The hypotheses formulated were verified by structural equation modelling.FindingsThe analysis reveals a four-dimensional motivational structure (ethics, efficiency, commercial and legitimacy) and three dimensions for the implementation of the FSMS (food safety management, analysis of hazards and control points and best practices). Motivations of an ethical and commercial nature have a positive effect on the degree of effective implementation, while those based on the search for legitimacy reveal a negative relationship.Originality/valueWhile most of the studies on the implementation of management systems are based on a dichotomous measurement of this process (companies with a management system compared to those without one, or companies certified according to a standard compared to those that are not), this study uses a continuous variable of the degree of effective implementation of the system's different dimensions or components. Little has so far been reported about why companies implement an FSMS, and here we not only identify their reasons but also assess those dimensions with the greatest impact.