The Andigena potatoes (Solanum tuberosum ssp.andigena) of the Commonwealth Potato Collection (C.P.C.) were screened for resistance to ‘non-pathotype A’ populations ofHeterodera rostochiensis. Three populations were used: Duddingston (pathotype B), Nocton (pathotype C) and Changed Little Ouse (pathotype C). Resistance was found in C.P.C. 2775, 2802 and 2805. C.P.C. 2775 also had resistance to pathotype A (Feltwell population) and appeared to have two dominant genes,H 1 giving resistance to pathotype A andH 3 giving resistance to pathotypes B and C. C.P.C. 2802 was susceptible to pathotype A and appeared to have only anH 3-type gene. C.P.C. 2805, which has not been investigated thoroughly because the plants lacked vigour, may also have anH 1 and anH 3 gene. The value of C.P.C. 2775, 2802 and 2805 for breeding nematode-resistant potatoes will only be known when they have been tested with further non-pathotype A populations and when the genetics of resistance have been investigated thoroughly.