The aim of the work was to determine the effect of potato harvest time on chemical composition of potato tubers and the texture of chips. Tuber samples of six potato varieties (Aster, Orlik, Mila, Irga, Bryza i Arkadia) harvested in three different terms: six weeks before proper harvest time, three weeks before and in their full physiological ripeness were the subject of investigation. Then chips were prepared of all varieties of harvested potatoes. It was possible to record that chemical composition of potatoes was changing with the degree of potato tubers ripeness. In all varieties of potatoes the content of starch and non-starch polysaccharides increased in proper harvest time. The biggest changes of starch content as related to harvest time were noted in potato tubers of Arkadia variety and the smallest ones were observed in Mila and Bryza variety. Hardness of produced chips increased with ripeness of tubers. More significant diversity in chips hardness was stated between the samples collected during the first and second harvest terms than beetwen those harvested in the second and the third term. The chips prepared of potato tubers of Mila and Bryza variety occurred to have the most permanent hardness, regardless their harvest time. In sensoric evaluation of chips texture the highest grades (5 points) obtained the chips made of potatoes harvested in the third term. The chips prepared of potatoes harvested earlier were characterized as showing oleic texture, while those made of potatoes harvested in their full physiological ripeness were satisfactorily crunchy.