In his article, the author presents the results of surveys on competitiveness in the retail trade in foods. As the basis for assessment of competitiveness there was adopted formation of value of the basket of foods being purchased in the trade network of the city of Olsztyn in 2004-2008. The subject matter of relevant comparisons was the shopping baskets comprised of 10 typed for surveys standard products as well as the baskets comprised of their substitutes. Registration of those goods was made on the representative research sample of trade outlets comprised of super- and hypermarkets as well as general stores and shops in bazaars. The surveys show that hypermarkets not only retain but also strengthen their competitive advantage in the market what is manifested in significantly lower purchasers' expenses on purchase of the products surveyed and the cheapest substitutes related to the entities representing small retailing trade.