The production of value-added chemicals from renewable sources, such as biomass-derived carbohydrates, is an emerging field. The amount of publications in the field of pentose and hexose conversion to furfural and hydroxymethylfurfural has considerably increased in the recent years. Most of these studies focus on using heterogeneous acid-catalysts to selectively convert these carbohydrates into the desired products at optimized yields. This review aims to summarize the most significant studies reporting the conversion of C-5 and C-6 carbohydrates using different structured materials. The final goal is to provide with a general overview of the broad spectrum of heterogeneous catalysts studies and the correlation between their physicochemical properties, with a special attention on the pore structure, and the catalytic activity under different reaction conditions, such as solvents or temperature. In the case of furfural, as it is already a commercial product, a short overview of the manufacturing process and the current improvements will also be given. The future studies reporting the carbohydrate dehydration reactions to furfural and HMF could take advantage of this study to select the physicochemical properties of the catalysts required to achieve their specific goals. (C) 2013 Elsevier B.V. All rights reserved.