As a result of the importance of commercial motor vehicle (CMV) transport internationally, much literature has concentrated on improving our understanding of the factors that influence CMV accident occurrence and severity. However, vehicle age, an important factor in practice, has been largely overlooked. In the present study the effects of vehicle age on road safety are investigated through accident rates and severity indices for CMVs of different age classes, using detailed accident reports for more than 13 000 CMV accidents in Greece. Findings suggest that older vehicles have a 4.5 times higher accident involvement probability in comparison with newer vehicles, while accidents involving older CMVs have a 4 times higher probability of resulting in a fatality. Further analysis suggests that the mean per capita cost to tax payers from CMV accidents surpasses 100A per year, more than half of which is attributed to older vehicles. Measures to mitigate the problem are suggested.