Complexation of the dye Direct Red 1 with a series of laurylamine surfactants with varying number of ethylene oxide units has been studied by voltammetry. From the measurement of the cathodic current of both dye and surfactant, the stability constants of the established equilibrium between the dye D, the surfactant S, and the dye-surfactant complex D-S can be calculated. The values of the stability constant K at 25 C calculated for a defined dye-surfactant stoichiometry depend on the number of ethylene oxide units incorporated by the surfactant. These constants decrease by one order of magnitude at 60 C maintaining the dependence on the number of ethylene oxide units.