This study examined whether a previously established (D. G. Laing & G. W. Francis, 1989) limited capacity to discriminate and identify the components of olfactory mixtures resulted from the participants' lack of familiarity with the task, training designed to optimize cognitive and perceptual performance, or professional experience in odor discrimination. The participants were a trained panel of 10 women (23-43 years old), and an expert panel of 8 male professional perfumers and flavorists (25-55 years old). The individual chemical stimuli were 7 common dissimilar odorants of equal moderate intensity. An air dilution olfactometer delivered a single odorant or a mixture containing up to 5 odorants. The results indicated that for both panels only 3 or 4 components of a complex mixture could be discriminated and identified and that this capacity could not be increased by training. Therefore, the limit may be imposed physiologically or by processing constraints.