While there is increasing knowledge regarding the role of sulfur in catalyst deactivation during steam reforming, much of the recent work remains focused on the development of sulfur tolerant catalysts while few investigations centers on understanding sulfur poisoning. In the current work, steam reforming of Jet A on a previously formulated multicomponent catalyst was studied to understand catalyst deactivation, primarily due to sulfur poisoning and carbon deposition. Jet A is a complex hydrocarbon mixture with a high concentration of aromatics, which are known to be active coke precursors, and the presence of several hundred ppm of sulfur. The catalyst was also tested for activity with simulated jet fuel (a mixture of paraffins and aromatics) with no sulfur for comparison purposes. The primary objective of the study was to gain insights into sulfur poisoning and carbon deposition during steam reforming of sulfur containing transportation fuel.