Seven bread wheat (Triticum aestivum L.) cultivars, one durum wheat (Triticum durum L.) cultivar, seven triticale cultivars and two rye cultivars (Secale cereale L.) were studied to aluminum toxicity using four different levels of this element in nutrient solutions at constant temperature (28 °C ± 1 °C). The tolerance was measured taking into account the root growth in an aluminum-free complete nutrient solution after a previous Al3+ treatment. With a toxic concentration of aluminum, the primary roots did not grow at all and remained thickned at the tip as a typical aluminum injury. The rye cultivars: Goyarowo and Branco were tolerant to 20 ppm of Al3+; the bread wheat cultivars Siete Cerros and Tobari and the durum wheat Cocorit were sensitive to 5 ppm of Al3+, BH-1146. IAC-5, BR-1 and IAC-18 were tolerant while the cultivar IAC-17 showed moderate tolerance to 5 ppm of Al3+; the triticale cultivars, PET-763, TCEP-77142, PFT-764, TCEP-77138, TCEP-77136, TCEP-75709 and Cynamon were tolerant to 5 ppm of Al3+. All wheat and triticale cultivars were very sensitive to 10 ppm of Al3+. These results showed the possibility to grow rye as an optional culture during the winter time, under acid soils with high aluminum, in the State of São Paulo, Brazil.