The electrocatalytical oxidation of hydrazine at low potential using tetracyanoquinodimethanide adsorbed on silica modified with titanium oxide was investigated by cyclic voltammetry and amperometry. The modified electrode was prepared modifying a carbon paste electrode employing lithium tetracyanoquinodimethanide adsorbed onto silica gel modified with titanium oxide. This electrode showed an excellent catalytic activity and stability for hydrazine oxidation. With this modified electrode, the oxidation potential of hydrazine was shifted toward less positive value, presenting a peak current much higher than those observed on a bare GC electrode. The linear response range, sensitivity and detection limit were, respectively, 2 up to 100 mu mol l(-1), 0.36 mu A l mu mol(-1), and 0.60 mu mol l(-1). The repeatability of the modified electrode evaluated in term of relative standard deviation was 4.2% for 10 measurements of 100 mu mol l(-1) hydrazine solution. The number of electrons involved in hydrazine oxidation ( 4), the heterogenous electron transfer rate constant (1.08 x 10(3) mol(-1) l s(-1)), and diffusion coefficient (5.9 x 10(-6) cm(2) s(-1)) were evaluated with a rotating disk electrode.115631638