Nine rye genotypes, two triticale, five bread wheat and one durum wheat were studied for aluminum tolerance in aerated nutrient solutions with six different levels of aluminum (0, 3, 6, 10, 15 and 20 mgL-1), under constant temperature at 25 ± 1oC and pH 4.0. Aluminum tolerance was evaluated by measuring the root growth in an aluminum-free complete nutrient solution after a treatment of 48 hours in an aluminum solution. All the rye cultivars Branco, Bagé, FA (In Chansti), Soron, Padrela, Montalegre, Vila Pouco de Aguiar, Gimonde and Lamego and the wheat cultivars BH-1146 and IAC-227 were considered tolerant because they showed root growth after treatment in solution containing 20 mgL-1 of Al3+. The rye genotypes Padrela, Montalegre and Vila Pouco de Aguiar were considered the most tolerant according to the index of relative tolerance. The triticale cultivars IAC-1 and CEP-15, and the bread wheat cultivars IAC-5 and IAC-24 presented an intermediate tolerance, showing root growth in the presence of 15 mgL-1 of Al3+, but no growth was found in the presence of 20. The cultivars Anahuac (bread wheat) and Yavaros "S" (durum wheat) were sensitive to Al3+, showing no root growth after treatment in solution containing 3 mgL-1 of Al3+. Key Words: rye, triticale, bread wheat, durum wheat, aluminum, toxicity