BackgroundSuicide continues to be a leading cause of death globally. Friends and family are considered best positioned to provide initial assistance if someone is suicidal. Expert consensus guidelines on how to do this were published in 2008. Re-developing these guidelines is necessary to ensure they contain the most current recommended helping actions and remain consistent with the suicide prevention literature.MethodsThe Delphi consensus method was used to determine the importance of including helping statements in the guidelines. These statements describe helping actions a member of the public can take, and information they should have, to help someone who is experiencing suicidal thoughts. Systematic searches of the available suicide prevention literature were carried out to find helping statements. Two expert panels, comprising 41 suicide prevention professionals and 35 consumer advocates respectively, rated each statement. Statements were accepted for inclusion in the guidelines if they were endorsed by at least 80% of each panel.ResultsOut of 436 statements, 164 were endorsed as appropriate helping actions in providing assistance to someone experiencing suicidal thoughts or engaging in suicidal behaviour. These statements were used to form the re-developed guidelines.ConclusionThe re-development of the guidelines has resulted in more comprehensive guidance than the earlier version, with the endorsement of 164 helping actions, compared to 30 previously. These guidelines will form the basis of a suicide prevention course aimed at educating members of the public on providing first aid to someone who is experiencing suicidal thoughts.Electronic supplementary materialThe online version of this article (doi:10.1186/s12888-014-0241-8) contains supplementary material, which is available to authorized users.