The nonnutritive sweetener sodium cyclopentylmethyl-sulfamate was fed to Wistar albino rats. The urine was collected for 3 days, combined, and examined (GLC) for the metabolites cyclopentyl-methylamine and cyclopentylmethanol. The percent conversion to these metabolites was 0.077 and 0.0102, respectively. The percent conversion to these to cyclopentylmethylamine was the lowest conversion to amine observed when compared to the metabolism of three other sweet sulfamates, cyclopentylsulfamate, cycloheptylsulfamate, and cyclooctylsulfamate, previously administered to rats. The average excretion of unmetabolized sulfamate was 15.4%. Sodium cyclopentylsulfamate was fed to rats over 9 days, and an analysis was carried out for the metabolites cyclopentylamine, cyclopentanone, and cyclopentanol. A decrease in the level of metabolites occurred after the first 3 days.