The Taylor dispersion technique is used to determine the diffusion coefficients of the ternary systems glucose + water + dilute methanol, ethanol, or acetone at 25 degrees C and up to a glucose mole fraction of 0.065. The dispersion of the injected solutes is recorded by a differential refractometer and an ultraviolet-visible detector. The diffusion coefficients are calculated directly by fitting the theoretical dispersion equations to about six experimental curves simultaneously. The precision of the diffusion coefficients is dependent on the relative detector sensitivities of the components. The determination of the main-diffusion coefficients is more precise than of the cross-diffusion coefficient (+/- 2% vs +/-5-10%).