A hydrogen economy, the long-term goal of visionary nations, has the potential to provide energy security, along with environmental and economic benefits. The concept of a hydrogen energy economy was first conceived at The Hydrogen Economy Miami Energy (THEME) Conference, held in March 1974 in Miami, Florida, where the International Association for Hydrogen Energy was established. Forty years later, advances in hydrogen technologies have led the world's most developed countries to invest extensively in preparation for a future hydrogen-based economy. However, the transition from a conventional petroleum-based energy economy to a hydrogen economy involves many uncertainties regarding concerns such as the development of efficient fuel cell technologies, problems in hydrogen production and distribution infrastructure, hydrogen safety issues, and the response of carbon-based fuel markets. This paper presents an assessment of the economic impact of hydrogen energy on the transportation and energy use sectors of Nigeria, along with implications for Greenhouse Gas (GHG) emissions. The analysis uses the Long range Energy Alternatives Planning (LEAP) technology database and model to simultaneously consider the impact of alternative and conventional technologies and fuels on these sectors. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.