The objective of the work reported in the article was to analyse the influence of the uncertainty of estimating the values of parameters of selected mathematical models, built to describe the relations between the pedestrian throw distance and the launch velocity gained by the pedestrian in result of being struck by the front part of the vehicle body. Within the work, the impact of changes in the pedestrian launch angle on the pedestrian launch velocity was investigated and the problems connected with choosing the value of the coefficient of friction between pedestrian’s clothing and the road surface were shown. The analysis presented may be useful in the reconstruction of an accident where a motor vehicle ran into a pedestrian.