It has been shown that hydroisomerization of an olefinic feed to an iso-paraffinic product can be performed in a single reactor using a platinum on mordenite (Pt-MOR) zeolite catalyst. This conversion finds application in a Fischer-Tropsch refinery where the syncrude is rich in olefins and conventional hydroisomerization would require hydrogenation of the feed as a feed pretreatment step. In order to demonstrate that the proposed process configuration is viable from a catalysis point of view, the hydroisomerization of 1-pentene over Pt-MOR has been investigated experimentally in the range 200-270C, 2MPa, WHSV 1-3h-1, and H2:1-pentene molar ratio of 3:1-5:1. The catalyst was stable during one week of continuous operation. The highest iso-pentane yield (69%) was obtained at 250C. Side reactions (dimerization and cracking) increased with increasing temperature, decreasing H2:1-pentene ratio, and increasing space velocity.