Abstract: Application of a Tecator FIA (flow injection analysis) method to determine nitrate and nitrate in milk products is discussed. Trials showed that this method permits easy, rapid and accurate analysis of nitrate and nitrite. Determination of low nitrite concentrations in cheese and baby foods requires some method modifications to achieve sufficient sensitivity. Using the modified method, the detection limit for nitrite in cheese is 0.1 mg/kg. In dried products with a high content of lactose or other compounds which pass through the dialysis membrane, a systematic positive error may occur of the order of 0.05-0.1 mg/kg product; the detection limit is therefore matrix-dependent. Recoveries of nitrate and nitrite (determined by the method of standard additions) are 95-100% for most products. For nitrate concentrations of 10 mg/kg DM and nitrite concentrations of 0.5 mg/kg DM, relative s.d. are approximately 5%.