To date passive lateral and longitudinal particle beam spreading systems are most representative of therapy systems in use worldwide. The absolute and relative dosimetry of these systems will be reviewed. Currently, however, the field of particle therapy is experiencing a technology shift to active beam delivery systems, simply termed scanning. The dosimetric characterization of scanning systems is by nature more complicated than with passive types. In some cases innovative solutions are required to adequately perform scanning system dosimetry. Details of the contemporary development of some of these solutions will be presented.