In 1996 at the Plant Breeding and Acclimatization Institute, Research Division Młochów breeding of improved parental lines started in order to accelerate the development of potato cultivars suitable for processing. Parental lines were derived from specific hybridizations between West-European or North-American cultivars with a high processing quality and our own genotypes with an increased dry matter content, light colour of fried product and multiply virus resistance (PVX, PVY, PVM, PLRV). Among eleven parental lines that were supplied to Polish breeders in 1999-2005, nine are „cold chipping” type with a light colour of fried product after a cold storage at 4-5ºC. A high potential advance of the released parental lines by selection for chip colour was expressed by the estimates of: genetic variance (δ²g), heritability (h²), progressin chip colour (R) and the presence of positive effects of general combining ability in pilot progenies. The valuable feature of the released parental lines in comparison with the leading foreign cultivars used in processing industry in Poland is their higher resistance to a common and necrotic strain of PVY.