A method for the simultaneous separation and determination of indole-3-acetic acid (IAA) and its primary metabolite, indole-3-acetylaspartic acid (IAAsp), in an extract from pea (Pisum sativum), is described. The technique used is capillary electrophoresis with fluorescence detection, the finally selected analytical parameters being: buffer 30 mM acetate, pH 4.5, injection volume 26 nl, high voltage 30 kV and excitation and emission wavelengths of 254 and 360 nm, respectively. The detection limits obtained were 18 nM (0.39 fmol) for IAA and 28 nM (0.73 fmol) for IAAsp. Sample preparation procedures have also been examined. The amounts of IAA and IAAsp in shoot apices of pea were determined to 1.9×10⁻¹⁰ and 1.1×10⁻¹⁰ mol/g fresh mass, respectively, corresponding to 33 ng/g fresh mass for both, using indole-3-butyric acid as an internal standard.