The paper analyses Italian hydrogen scenarios to meet climate change, environmental and energy security issues. An Italy-Markal model was used to analyse the national energy-environment up to 2050. About 40 specific hydrogen technologies were considered, reproducing the main chains of production, transport and consumption, with a focus on transport applications. The analysis is based on the Baseline and Alternative scenario results, where hydrogen reaches a significant share. The two scenarios constitute the starting points to analyse the hydrogen potential among the possible energy policy options. The energy demand in the Baseline scenario reaches values around 240 Mtoe at 2030, with an average annual growth of 0.9%. The Alternative scenario reduces consumption down to 220 Mtoe and stabilizes the CO2 emissions. The Alternative scenario expects a rapid increase of hydrogen vehicles in 2030, up to 2.5 million, corresponding to 1 Mtoe of hydrogen consumption. A sensitivity analysis shows that the results are rather robust. (c) 2007 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.