Abstract: Glycollate is determined by the action of L-2-hydroxyacid oxidase. The H2O2 produced is detected in the presence of peroxidase by use of an indicator reaction with 3-methyl-2-benzothiazoline hydrazine and NN-dimethylaniline. Urine samples are treated with activated charcoal before analysis to reduce interferences of reducing substances. Correction must be made for lactate in urine, which interferes. An accurate, precise and sensitive continuous-flow system, with use of enzyme immobilized on the inner surface of nylon tubing is described, but this is unsuitable for routine use because of the instability of the enzyme. A semi-automated procedure is described for the Cobas-Bio centrifugal analyzer. with use of enzyme in solution. Recovery by this method was 96% and within- and between-batch coefficient of variation were <2 and <5%, respectively. The normal reference interval for urinary excretion of glycollate is 0.13 to 1.31 mmol day-1.