In this paper, the multi-walled carbon nanotube (MWCNT)-polystyrene composite modified Pt electrode that is capable of serving as an efficient electrochemical gas sensor upon direct exposure to trace quantity of toxic gases like SO2 and H2S with distinct electrochemical response is reported. Unlike other CNT-composite modified electrodes this new composite device relies on the use of MWCNTs as the sole conducting component, the other component polystyrene is non-conducting.