The present study describes the costs for implementation of food safety systems in a small dairy plant located in the central region of the state of São Paulo, Brazil. The steps involved in the implementation of a food safety system include a diagnosis of the prerequisites, implementation of the good manufacturing practices, standard sanitation operating procedures (SSOPs), training of the food handlers and hazard analysis and critical control points (HACCP). After implementation of the food safety system, the total cost of implementing the food safety system was US$ 61,812.00, signifying an impact of US$ 3.81/t of yogurt packed (0.5% of the production costs). The resources used for investment signified an additional US$ 12.92/t (1.5% of the cost per kg of yogurt packed). It was concluded that the application of HACCP considered in this study for the yogurt production line presented an adequate cost-benefit relationship, which would improve with the passage of time and with the improvement and sedimentation of the culture of food safety in the company.