A simple method for the preparation of 3′-sialyllactose from normal human urine is described. The method for the collection of sialooligosaccharides is based on adsorption on charcoal followed by elution with a mixture of ethanol, pyridine, and water. The sialooligosaccharide mixture is then fractionated by means of gel filtration on Sephadex G-25 and the low molecular weight fraction is further fractionated on Dowex 1 (eluted with pyridinium acetate) to give five fractions. The last fraction contains almost pure 3′-sialyllactose.