This paper analyses the energy consumption and CO2 emissions of biological hydrogen production from sugarcane and potato peels using life cycle assessment methodology for the Portuguese scenario. Potato peels are assumed to be produced locally from Portuguese potato cultivation. Sugarcane is assumed to be imported from Brazil and fermented in Portugal. The uncertainty is quantified by a Monte Carlo approach. Biohydrogen was compared with natural gas reforming, electrolysis and other energy resources such as diesel and electricity. Between bioH(2) feedstocks, sugarcane stands out with the lowest values for energy consumption and CO2 emissions with 0.30-0.34 MJ of consumed energy and 24-31 g of CO2 emitted per 1 MJ of H-2 produced. However these results do not have a major contribution to the Portuguese energy independency problem. On the other hand potato peels feedstocks are more attractive, presenting values of 0.49-0.61 MJ/MJ(H2) and 60-77 gCO(2)/MJ(H2). According to Portuguese production capabilities, it is estimated that bio-hydrogen will be able to supply 3100 vehicles of a typical Portuguese urban taxi fleet or up to 1.4 million passenger cars with a daily commuting distance of 30 km. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.