The relative efficacy of citric, malic, malonic, oxalic and succinic acids, and deferoxamine mesylate (DFOA) on the toxicity, distribution and excretion in mice exposed to aluminum were compared. Chelating agents were administered intraperitoneally at a dose equal to one-fourth of their respective LD50. To determine the effect of the various chelators on the toxicity of aluminum, various doses of aluminum nitrate (938-3188 mg/kg) were administered intraperitoneally, followed by one of the chelators. Survival was recorded at the end of 14 days. Malic and succinic acids were the most effective. Malic acid and DFOA were the most effective in increasing the urinary excretion of aluminum. Citric acid was the most effective in increasing the faecal excretion of aluminum. Malonic, oxalic and succinic acids had no overall beneficial effects. Citric acid would appear to be the most effective agent of those tested in the prevention of acute aluminium intoxication. However, before the use of these compounds in human aluminium intoxication is possible, further investigations including the effects of these chelators after chronic aluminium intoxication are required.