The authors describe the method used in Argentina for quantification of risk in controls of the potency and innocuity of foot and mouth disease vaccine. Quantitative risk analysis is a relatively new tool in the animal health field, and is in line with the principles of transparency and equivalency of the Sanitary and Phytosanitary Agreement of the Uruguay Round of the General Agreement on Tariffs and Trade (GATT: now World Trade Organisation [WTO]). The risk assessment is presented through a description of the steps involved in manufacturing the vaccine, and the controls performed by the manufacturer and by the National Health Animal Service (Servicio Nacional de Sanidad Animal: SENASA). The adverse situation is considered as the lack of potency or innocuity of the vaccine, and the risk is estimated using a combination of the Monte Carlo simulation and the application of a Bayesian model.