The inheritance of frost hardiness and cold acclimation potential traits was studied in three segregating populations derived from a cross between Solanum commersonii Dun. PI 243503 (cmm) and Solanum cardiophyllum Lindl., PI 184762(cph), two parental genotypes with contrasting frost hardiness and cold acclimtin potential. The levels of frost hardiness and cold acclimation potential were expressed as the LT50, the temperature at which 50% of the cells in leaf discs were killed, as measured by the ion leakage method, following a controllled freeze test. There was considerable variation in both frost hardiness and cold acclimtion potentil in all three segregating populations (F1, F1 x cmm, and F1 x cph). Frost hardiness and cold acclimation potential were not correlated, suggesting that these two traits are under independent genetic control. The analysis of generation means indicated that the variation for both traits could be best explained by an additive-dominance model, with additive gene effects the most importnt. Broad-sense heritability was 0.73 and 0.74 in the F1 population, for frost hardiness and cold acclimation potential, respectively, and was 0.85 for either trait in the F1 x cmm population, indicating that these two traits are highly inheritable. Our results suggest that it should that it should be possible to incorporate the forst hardiness and cold acclimation traits from S. commersonii into cultivated potato species.