This paper presents a comprehensive methodology for evaluating the economic attractiveness of gas-to-liquid (GTL) technology in a gas rich country like Qatar. The Qatari gas volume needed to fully satisfy the projected long-term market demand of GTL products (mainly diesel oil) in the Asia-Pacific region is evaluated. Based on the state-of-the-art GTL technology, the number, size and the commissioning dates of GTL plants required for that purpose are determined along with the associated investment and running costs. The economic attractiveness of GTL investment is evaluated based on the internal rate of return, and the impact of adopting large-scale GTL projects on Qatar oil refining industry is assessed. Sensitivity analyses are conducted using several scenarios to account for variations in GTL premium, capital cost, operation and maintenance cost and cost of gas feedstock. (C) 2007 Elsevier Ltd. All rights reserved.