The effect of gas diffusion layer compositions on the performance of liquid feed direct methanol fuel cell has been investigated. Cathode diffusion layers consisting of carbon paper with different microporous layer compositions have been fabricated. Specifically, we have modified the carbon material used in microporous layers. Morphological and textural properties of different cathode diffusion layers were characterized and related to the performance obtained in single cell experiments. We have found that using a microporous layer made with an acetylene black instead of a furnace carbon black resulted in higher cell voltages in the entire current density region, as well as, higher maximum power density. This was attributed in first instance to the decrease of mass transfer resistance in the oxygen diffusion layer as a consequence of the microstructure of microporous layer.