The adsorption of the antineoplastic drug mitomycin C (MC) on the hanging mercury drop electrode (HMDE) surface by means of stripping voltammetry measurements is studied. With this technique, a cathodic peak is obtained at -0.47 V (vs Ag/AgCl) in phosphate buffer pH 7.1 after accumulation onto HMDE surface by applying -0.35V. Peak current variations with the accumulation time, MC concentration, and temperature are presented. The Langmiuir isotherm is employed for adjusting the experimental results, and the values of the Gibbs free energy, enthalpy, and entropy of adsorption are calculated, the adsorption process being entropically governed. The results and data presented can provide useful information on the mechanism of penetration across the cellular membrane, which is of clinical interest since MC exerts its antineoplastic activity by interaction with biological membranes.