The production of liquid transportation fuels such as gasoline, diesel and jet fuel from petroleum involves the use of a variety of catalytic processes. Although the petroleum refining industry is quite mature, fuel composition requirements continue to evolve with time in response to environmental legislation and changes in engine design. In addition, petroleum feedstocks are becoming heavier and more sour with time. New technology is emerging that allows efficient conversion of natural gas to liquid hydrocarbon fuels. Taken together, these changes pose considerable challenges to the refining industry and significant advances in catalysis are needed to meet the challenge.