Nicotine and tobacco products contain characterizing flavours that mask their harshness, ease their use and increase their acceptability. Recent estimates indicate that flavour use is common, and thousands of flavours are now available for electronic nicotine delivery systems. Non-traditional flavours, like fruit and confectionery, are particularly appealing to young people, and use of these flavours is also increasing among adults, especially among adult smokers who are trying to quit smoking. Flavours in all nicotine and tobacco products have been shown not only to increase the appeal and first use of the products but may also contribute to extent of use, progression from experimental to regular use and dependence. Another concern is that chemicals in flavours may contribute to the toxicity of these products. Flavours are not regulated uniformly in nicotine and tobacco products or among countries. Some countries ban all flavours in all products, others have bans on only some flavours (e.g. excluding menthol), while others include only certain products (e.g. traditional products, such as cigarettes and smokeless tobacco) in regulations. This report on flavours in nicotine and tobacco products calls for adoption of common terminology for flavours in nicotine and tobacco products and consideration of policy for reducing the availability of flavoured nicotine and tobacco products on the market to those for which there is clear evidence of benefit in assisting smokers in quitting use of traditional smoked tobacco products.