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The objective of this work is to determine whether there are differences between cardoon varieties in the content of bioactive substances. Different varieties of cardoon were selected from the collection owned by the ITGA of Navarre. The varieties used in this study were: 'Blanco de Peralta', 'El Cortijo', 'Lleno de Espana', 'Rojo de Agreda', 'Blanco de Valencia', 'Verde de Peralta', 'Bianco Inerme', 'Blanco Plain Inerme'. Harvesting was done on 7 April 2008. Samples of these varieties were analyzed to determine the major biochemical compounds. For each variety, various parameters have been determined: vitamins (C, E and B9), carotenoids (lutein, zeaxanthin, lycopene, α-carotene and β-carotene), polyphenols (quercetin, rutin, resveratrol, myricetin, catechin, epicatechin, caffeic acid and gallic acid) and simple sugars (glucose, fructose, sucrose, maltose and lactose) quantified by high performance liquid chromatography. Other parameters were analyzed such as total antioxidant capacity (TAC) by the diphenyl-picryl hydrazyl test (DPPH), and free and total polyphenols by Folin-Ciocalteu assay. Finally, the dietary fibre content of the samples was determined by enzymatic digestion. The results show that the compounds allowing the distinction between cardoon varieties analyzed, are gallic acid, glucose, fructose, TAC, free polyphenols, polyphenols and dietary fibre. The maximum concentration for each of these parameters was observed in different varieties. 'Inerme Bianco' presents greater concentration of gallic acid and polyphenols, 'Blanco de Peralta' contains higher sugar content, 'Verde de Peralta' has the greatest antioxidant capacity and 'Rojo de Agreda' presents greater concentration of free polyphenols. Finally, 'Lleno de Espana' has the highest percentage of dietary fibre. Therefore, we can’t conclude which cardoon variety is better than another from the standpoint of the content in bioactive compounds; we should particularly investigate the bioactive compound in which we are interested.