European Union Regulation 258/97 defines novel foods as food products and food ingredients that have not been consumed to a significant degree in the European Union before May 1997. However, there are new foods that for some reason are not considered as novel foods, though we think that safety of these products is not always a priori established. We defined a 'grey area' which consists of such foods, and the present paper intends to raise awareness of this 'grey area' of unidentified novel foods. The grey area of novel foods is divided into two categories: (1) food products or ingredients for which the current Regulation leaves too much space for different interpretations and (2) food products or ingredients that are not novel according to the current Regulation, because the current Regulation contains gaps. These categories are illustrated by means of products already on the market in The Netherlands. We found about two dozen examples of products that had not been identified as novel foods according the current Regulation, yet could be considered to be classified as novel foods and hence for which a safety evaluation (toxicological and/or nutritional) would be indicated.