Classical swine fever virus (CSFV) is a highly infectious disease of pigs, which has devastating economic and social consequences. To minimise the potential for future outbreaks, it is important to assess the risk of CSFV introduction to the UK via porcine products. In doing so, the first aim was to determine the oral infectious dose 50% (oral PID50) of a highly virulent strain of CSFV. Previous work carried out at AHVLA has identified the oral PID50 of a moderately virulent CSFY strain, and so the aim of this study was to evaluate whether virulent strains have a lower or similar infectious dose, in order to represent a worst-case .scenario of susceptible pigs consuming pork containing CSFV. Through oral inoculation of pigs, the oral PIDso of Brescia was found to be 105.47 TCID50 with a 95% confidence interval of 105.1 to 105.8 TCID50.