Twelve potato varieties imported from Holland (Prinslander, Irene, Froma, and Barima), Germany (Merkur, Sabina, Linda, and Concordia), and Sweden (Konsuragis, Eigenheimer, Voran, and Jätte-Bintje) were compared in six experiments carried out at three different localities in the state of São Paulo (Campinas, Louveira, and Capão Bonito). The experiments were planted twice a year, once during the so-called dry season (March lo July), and another time during the rainy season (September to March). The following results were obtained: a) plantings made in the dry season had a good stand, whereas this was poor in the rainy season for the late varieties, Voran and Sabina; b) Prinslander and Konsuragis showed good drought resistance, but Barima and Linda did not; c) Linda, Voran, and Merkur showed resistance to Phytophthora blight, the first-mentioned variety being the most resistant; Bintje was susceptible to the same disease. The varieties Voran, Irene, Prinslander, and Barima were susceptible to early blight; d) Merkur and Konsuragis were the highest yielders in the two planting seasons, but iu plantings made in the rainy season Eigenheimer, Barhna, Coueordia, and Jiitte-Bintje yielded as well as them.