This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

The main objective of the review is to assess the effects of salt fluoridation in preventing caries in the population. Specific objectives include:

• To evaluate the effectiveness and safety of fluoridated salt intervention compared with control (non‐fluoridated salt), as a means of delivering fluoride systemically on a community basis, for preventing dental caries in children, adolescents and adults

• To examine whether the effectiveness of fluoridated salt on caries prevention is influenced by types of salt fluoridation schemes adopted and other particular intervention features, by initial caries levels and other relevant population characteristics, geographical regions/climates, and by exposure to other non‐systemically delivered fluorides (such as toothpastes)

• To evaluate the effectiveness of fluoridated salt compared with water or milk fluoridation (differential effect).