Fuel conversion to hydrogen is an important part of most fuel cell systems. The paper describes the available technologies for conversion of hydrocarbons and alcohols. The endothermic steam reforming catalysts and processes as well as autothermal reforming are proven technologies. Recent developments include catalytic partial oxidation. The integration of the fuel processing with the fuel cell represents a task with requirements depending on each type of fuel cell and application. The automotive use of fuel cells is at present a special challenge. The optimum fuel for stationary plants is natural gas (if available), whereas light naphtha appears to be the choice for automotive use.