A simple automated assay was described for the determination of serum amylase using a chromogenic substrate. The reaction was stopped by filtration across a cellulose nitrate membrane. The analytic parameters of this method were studied. Repeatability, reproducibility and precision were convenient. The calibration curve was linear up to 850 U/I. An excellent correlation was obtained after comparison with the manual method (Phadebas amylase test). The effects of haemolysis and very high ascorbic concentrations of bilirubin, glucose, uric acid and ascorbic acid were negligible on the value measured. The serum turbidity was alone to induce a variation by excess.