The aim of the experiment, conducted from 2005 to 2006, was to determine the effect of planting date (spring, summer/fall) and method (seedlings, direct sowing) on the content of dry matter, selected organic components and nitrates in the heads of Italian chicory radicchio, cv. Palla Rossa 3. Statistical analysis revealed that both experimental factors had a significant effect on the content of dry matter and simple sugars in the edible parts of radicchio. Dry matter content was significantly affected by planting method, while the concentration of total sugars – by planting date. Chemical analysis of the harvested plant material indicated that radicchio grown in the spring contained more dry matter, L-ascorbic acid, simple sugars and total sugars. Plants obtained from seedlings accumulated more L-ascorbic acid and simple sugars, whereas those grown from directly sown seeds contained more dry matter and total sugars. The nitrate content of radicchio heads was found to be significantly dependent on both experimental factors. A significantly higher (by over 33%) concentration of nitrates was recorded in the edible parts of radicchio grown in the summer/fall. The impact of planting method on nitrate content was less noticeable, but radicchio plants grown from directly sown seeds accumulated more nitrates (by almost 11% on average) than those obtained from seedlings. The interaction between the analyzed factors had a significant effect on the bioaccumulation of dry matter, L-ascorbic acid, simple sugars, total sugars and nitrates.