1. The concentration of taurine in the diets, plasma, urine and breast milk were measured in vegans and age- and sex-matched omnivore controls. Plasma and urinary amino acid concentrations were also determined. 2. Taurine was absent from the vegan diet and occurred in variable amounts in the diets of the omnivores. Urinary taurine levels were less than half those of the omnivores but plasma and breast-milk levels were only slightly lower. 3. Dietary energy intakes were similar in the vegans and omnivores, but protein intakes tended to be lower in the vegans.