Breeding for resistance to Globodera pallida, at the International Potato Center (CIP), is directed at pathotypes P4A and P5A. The polygenic nature of resistance and the variability of pathotypes complicate breeding and testing for resistance. Recurrent selection for resistance genes and for agronomic characteristics is used to increase resistant gene frequency in potato populations. Mass seedling screening, as an early indicator of segregation ratios in a progeny, and a petri‐plate technique for accurate assessment of resistance in potato clones have proven to be useful aids in selecting for resistance. Clones with partial resistance could be grown by farmers under certain conditions; partial resistance may also be useful in breeding programmes. New differential or tester clones which are better adapted and resistant to P5A populations should be utilized in the Andean region. Although Solanum tuberosum ssp. andigena has been the main source of resistance, especially to pathotype P5A, the CIP breeding programme should now turn to wild species in order to broaden the base of resistance. Copyright © 1985, Wiley Blackwell. All rights reserved