The excretion and metabolism of ¹⁴C-sucralose has been investigated in mice following intravenous and oral administration. A 20mg/kg intravenous dose was rapidly excreted mainly in the urine (80% in 5 days). After 100, 1500 and 3000mg/kg oral doses of ¹⁴C-sucralose, means of 23%, 15% and 16% of the dose, respectively, were excreted in the urine during 5 days. Comparison with the intravenous dose indicated that 20–30% of the oral doses was absorbed. Sucralose was excreted almost entirely unchanged and represented more than 80–90% of the radioactivity in all urine and faeces samples. Only two minor metabolites were detected, representing 2–8% of urine radioactivity.