Background: Suicide and suicide-related behaviours are major public health concerns in Australia and worldwide. One universal intervention that has received an increased focus as a means of preventing suicide is the use of media campaigns. There is, however, a lack of understanding of the kinds of campaign messages that are safe and effective. The current paper aims to expand on this knowledge. The study objectives were to: (1) explore what suicide prevention experts consider to be essential characteristics of effective and safe suicide media campaigns; (2) develop suicide prevention media messages; and (3) explore the impact that these messages might have on different audiences. Methods: We conducted a workshop in July 2015 which was attended by 21 experts (professionals with knowledge about suicide prevention and/or media campaigns, and people with a lived experience of suicide). The experts were split into three groups, and each group developed a suicide prevention message for one of the following target audiences: people at risk of suicide; family and peers of people at risk of suicide; and people bereaved by suicide. Results: The three groups generally agreed that these messages had to include two key characteristics: (1) validate or reflect the target group's issues and needs; and (2) promote help-seeking behaviours. They noted, however, that messages that might have a positive impact for one target audience might inadvertently have a negative impact for other target audiences. In particular, they were concerned that messages designed for family and peers about being supportive and looking for warning signs might leave those who had been bereaved by suicide feeling isolated, guilty or traumatised. Workshop participants highlighted that gaps exist in relation to the use of appropriate language, were unsure of how to create destigmatising messages without normalising or sensationalising suicide and commented on the lack of evaluative evidence for the efficacy of media campaigns. Conclusions: Developing suicide prevention messages is complex and target and non-target audiences may interpret these messages differently to the way they were intended and the impact of such messaging may be detrimental. Caution needs to be applied when developing suicide prevention messages.