A review of the literature published prior to July 1991 covers the occurrence and formation of non‐volatileN‐nitrosamines occurring in foods and beverages. The presence of identified volatile and non‐volatileN‐nitrosamines accounts for less than 10% of the total apparentN‐nitrosamine concentration.N‐Nitrosoproline andN‐nitrosothiazolidine‐4‐carboxylic acid are the most commonly identified non‐volatileN‐nitrosamines in the diet. Non‐volatileN‐nitrosamines account for 12 of the 21 currently identifiedN‐nitroso compounds in foods and beverages.