This book provides an updated list of the vascular flora of the National Park of Abruzzo, Lazio and Molise, incorporating the latest nomenclatural and floristic findings. The list of plants was extrapolated from a geographic database including all data from floristic or vegetational references and herbarium specimens concerning the Park area. This data storage tool was obtained from the database of Abruzzo vascular flora (Conti et al. 2010) and adapted to the study area by adding those areas of the Park falling in the regions of Lazio and Molise and their accompanying floristic and vegetational data. Analysis of the data has allowed gaps in the floristic knowledge of the Park, such as comparatively or completely unexplored areas, to be identified, together with those species records that still require confirmation and/or further study. On the basis of these deductions, fieldwork aimed at the collection of new floristic data was carried out. Verification of the correct identification of herbarium specimens collected in the past, as well as a systematic study of critical genera, were also important priorities.