A study was undertaken to assess the nutritional value of tubers of transgenic lines of potato cv. Desiree with repression of a and c isoforms of 14-3-3 proteins obtained by means of antisense transformations. Isoforms of 14-3-3 protein are responsible for metabolism of carbohydrates, amino acids and calcium. Repression of that protein, i.e. reduction of its synthesis in a potato plant, results in: a decrease in total protein content of tuber with a slight but favourable change in the amino acid profile, enhanced synthesis of starch, small differentiation in contents of minerals – diminished concentrations of Fe, P, and Ca. The 30% addition of dried transgenic potato tubers with repression of isoform a, c as well as a and c of 14-3-3 protein was found not to affect values of digestibility coefficients of nutrients. Repression of 14-3-3 protein was demonstrated to affect diversification of the chemical composition of tuber and contents of nutrients only to a small extent, without diminishing the nutritional value of potato tubers.