This paper reports an analysis procedure for the evaluation of the features of the motion of blocks detaching from a steep rock wall and traveling down the slope below. Starting from the execution of real scale rock fall tests, carried out on two slopes having different morphology and lithology, the paper describes the methodology used for test interpretation and a procedure for the evaluation of the parameters best suited to the description of rock fall motion. The influence of the parameters assessed on the prediction of the rock fall trajectory was also investigated using twodimensional and three-dimensional numerical models. These models were calibrated by means of a back analysis of the in situ tests, which also allowed the evaluation of the uncertainties involved in the parameters experimentally estimated.