CRASH3 is a computer program that enables a vehicle’s change of velocity during a crash to be deduced from the observed damage to the vehicle(s) involved. Along with other programs that share similar mathematical techniques, it is widely used internationally, particularly by groups and individuals who have access to damaged vehicles but not the accident scene: and it is applied to a wide range of vehicles and accident circumstances. Crash tests conducted under controlled conditions provide an opportunity to assess the program’s accuracy. In this paper CRASH3 is applied to vehicles tested during 1996-98 in the first three phases of the EuroNCAP program. This includes results from 26 models tested in 64 km/h offset frontal impacts and 50 km/h side impacts. On average, velocity changes were underestimated by 1 km/h for the side test and 7 km/h for the frontal test–this includes the effect of a special treatment of deformable barriers not available in the standard program.