This invention provides a process for producing hydrocarbons. The process involves contacting a feed stream comprising hydrogen and carbon monoxide with a catalyst in a reaction zone maintained at conversion-promoting conditions effective to produce an effluent stream comprising hydrocarbons, and uses a catalyst including (a) at least one catalytic metal for Fischer-Tropsch reactions (e.g., iron, cobalt, nickel and/or ruthenium) and (b) a non-layered mesoporous support which exhibits an X-ray diffraction after calcination that has at least one peak at a d-spacing of greater than 18 .ANG.ngstrom units.