In this study, the influences of different operational conditions such as cell temperature, sodium hydroxide concentration, oxidant conditions and catalyst loading on the performance of direct borohydride fuel cell which consisted of Pd/C anode, Pt/C cathode and Na+ form Nafion membrane as the electrolyte were investigated. The experimental results showed that the power density increased by increasing the temperature and increasing the flow rate of oxidant. Furthermore, it was found that 20 wt.% of NaOH concentration was optimum for DBFC operation. When oxygen was used as oxidant instead of air, better performance was observed. Experiments also showed that electrochemical performance was not considerably affected by humidification levels. An enhanced power density was found by increasing the loading of anodic catalyst. In the present study, a maximum power density of 27.6 mWcm(-2) at a cell voltage of 0.85V was achieved at 55 mA cm(-2) at 6 degrees C when humidified air was used. (c) 2008 Elsevier B.V. All rights reserved.