In the present work, the electrochemical behavior of an anticancer drug, gemcitabine hydrochloride (GMB) was studied in the presence of a surface active agent (surfactant) at carbon paste electrode (CPE). GMB showed an oxidation peak at 1.101 V. The presence of sodium dodecyl sulfate (SDS) in the electrolyte was found to enhance the oxidation signal of GMB at CPE. The oxidation peak current of GMB in the presence of SDS was observed to be the function of accumulation time, scan rate, pH of the medium, and concentration of GMB. Accumulation time greatly influenced the peak current but did not exhibit significant influence on the peak potential. Based on this, a novel, sensitive, and convenient differential pulse voltammetric method was developed for the determination of GMB in the concentration range of 5.0 x 10(-8)-3.0 x 10(-4) M with a limit of detection value of 8.2 x 10(-9) M. The proposed procedure was successfully applied for the determination of GMB in pharmaceutical formulations and spiked biological samples.