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Two aluminum (Al)-resistant (Atlas 66, Maringa) and two Al-sensitive (Roblin, Katepwa) cultivars of Triticum aestivum (wheat) were grown under aseptic conditions in the presence and absence of Al to evaluate the potential role of organic anion exudates in conferring resistance to Al. Five organic anions, α-ketoglutarate, citrate, malate, succinate and fumarate, were commonly detected in the root exudates, but only malate and succinate were consistently exuded in all cultivars under all treatments. Under control conditions, malate was exuded in higher quantities from roots of Al-resistant cultivars (Atlas 66 and Maringa), compared with the Al-sensitive cultivars. Exposure to 100 μM Al increased exudation of malate from roots of Al-resistant cultivars by 100–120 %, while in the Al-sensitive cultivars, exudation of malate was reduced. A decrease in exudation of succinate was observed in Atlas 66 and Maringa with 100 …