Two risk assessments using stochastic modelling technique were conducted regarding the hypothetical import of marker-vaccinated animals into Switzerland from countries where an official eradication programme was in place. By using scenario trees and collecting information from literature and experts, models were developed for Aujeszky's disease (AD) and Infectious bovine rhinotracheitis (IBR), respectively. As Switzerland is recognised as free from both diseases the introduction of the virus would lead to massive economic losses. The aim of the project was to provide decision makers and risk management with recommendations for possible future import scenarios.