According to art. 3.3 of the Kyoto Protocol, Italy, like other Parties included in Annex I, shall report the net changes in greenhouse gas emissions by sources and removals by sinks resulting from afforestation, reforestation and deforestation activities (ARD). To evaluate these activities, Italy has to elaborate methods to estimate the conversion of non-forested to forested land, occurred after 31 December 1989. The aim of this study was to test a methodology to estimate the ARD activities. The approach was experimented in the Comunità Montana del Grappa (about 10500 ha) considered as a pilot area in the Prealpine region (NE Italy). The land-use change relative to the forest area was assessed by multitemporal classification of 1131 sampling points on orthocorrected aerial photos relative to 1991, 1996 and 1999. The forest area based on different definitions (minimum land cover equal to 10%, 20% or 30% and minimum surface equal to 2000 m2 or 5000 m2) was also assessed. Between 1991 and 1999, the total increment of the forest area was equal to 224 ha. However, the estimated increment was strongly related to the minimum surface (2000 m2 vs 5000 m2) of the forest definition. The proposed procedure was relatively easy to implement and highlighted the role of ARD and revegetation to attain the goals appointed from the Kyoto Protocol.