The objective of this paper was to compare contents of non-starch polysaccharides and lignin in potato tubers in different stages of the French fries industrial processing. Samples of potato tubers, strips, and French fries were taken from five points located within a French fries production line in one factory. The total content of non-starch polysaccharides and lignin, and their particular fractions in potatoes were changing during the French fries processing. It was stated that blanching and frying processes generated the highest changes in potato tubers. Technological processes appeared to have the lowest destructive impact on the cellulose, hemicelluloses, and lignin content in analysed potatoes.