A quantitative risk analysis is presented for road transportation of ethylene oxide. The procedure is outlined, discussing the amount and depth of information required. Based on analysis of the data relevant to accident frequency, consequences of historical accidents, meteorological conditions and resident population, the route was divided into a number of portions. Then, reference was made to a couple of weather conditions, assuming two typical release sizes and the complete series of possible outcome predictions for each release, which were estimated using a commercial software package for consequence analysis. All the information was combined to give, directly, the individual risk, as a function of the distance from the route, and the societal risk (F-N curve), using a simple computer routine. The results showed that the examined transportation case represented a real hazard for the population and some mitigative actions were proposed, testing their effectiveness.