In 2010, the Latium Regional Administration promoted a systematic study for the seismic microzonation of its Municipalities, according to the official national and regional guidelines. This activity was co-funded by the National Department of Civil Protection (DPC) following the issue of the National rule OPCM 3907/2010. A Working Group including researchers from Latium Regional Administration, ENEA and the Department of Earth Sciences of the 'Sapienza' University of Rome performed the studies in some municipalities characterized by the most severe level of seismic hazard. The activity was carried out on the basis of both archive geotechnical data and original geophysical surveys. The whole municipal territory was divided in stable areas, where no further analysis is required, and areas prone to stratigraphic or topographic amplification, as well as to earthquake-induced phenomena such as landslides, sinkholes, liquefaction and seiche. The experienced approach highlighted some critical features in the microzonation methodology that encourage the refinement of the operative procedures. © 2013 WIT Press.