Traditional Korean soysauce samples were collected from households in Chinju, Gyeongnam, Korea and analysed for volatileN‐nitrosamines. Five of 24 samples contained NDMA (range = 1–6–10–4μg/1) which was the only volatileN‐nitroso compound found. Soysauce made from well water contained NDMA more often (4 of 6 samples) than soysauce made from tap water (1 of 18). This suggests that the water source is a determinate in the NDMA content of soysauce, probably due to a higher nitrate content of well water. The source of salt used did not clearly influence NDMA content. Soysauce was prepared in the laboratory using traditional methods but with 0 to 400 mg/1 nitrate and in some cases made 6.5 to 65 mM in ascorbic acid and fermented for 120 days. The NDMA content of the samples was positively correlated with increasing nitrate concentration. Nitrate at 400 mg/1 resulted in an NDMA content of 203μg/1. Ascorbic acid substantially inhibited NDMA formation. All samples contained large numbers of nitrate reductase‐containing organisms (>1 × 107CFU/ml).