We analyse the volume distribution of natural rock falls on different geological settings, i.e. calcareous cliffs in the French Alps, Grenoble area and granite Yosemite cliffs, California sierra and differnt volume range i.e. regional and word wide catalogs. Contrary to previous studies that inlcluded several types of landslides we restrict our analysis to rock fall sources which originated on sub vertical cliffs. For the three data sets we find that the rockfall volumes follow a power law distribution with a similar exponet value withing error bars.