Carbon dioxide gas management is an important issue in the development of the liquid feed direct methanol fuel cell. Data from a flow visualisation study, designed to study carbon dioxide gas evolution and flow behaviour are reported. Two different cell designs were used, one based on a simple parallel Flow channel concept and the second based on a heat exchanger design concept. With the aid of a high-speed video camera, appropriate computer software and transparent acrylic cells, gas evolution was recorded in a fuel cell working environment. The influence of current density and liquid flow rate are considered. Gas evolution mechanisms and gas management techniques are discussed. The effect of scale-up on the power performance of the parallel flow channel cell is reported.