BACKGROUND: It is widely recognised that mental health policies should be developed in consultation with those tasked with their implementation and the users affected by them. In the South African legislative context public participation in policymaking is assumed, with little guidance on how to conduct consultation processes, nor how to use consultation inputs in policy decisions. METHODS: The South African Mental Health Policy Framework and Strategic Plan was adopted in 2013 after an extensive consultation process. Focussing on the 2012 provincial and national consultation summit, this case-study conducted key informant interviews and undertook documentary analysis to explore the process through which consultation inputs were-or were not-transferred to inform this policy. Between 2013 and 2016 seven interviews were conducted, and 11 documents (policy drafts and summit outputs) and transcripts of 23 audio-recorded sessions from the national summit were analysed. RESULTS: Findings revealed that no substantive changes were made to the mental health policy following the consultation summits. There do not seem to have been systematic processes for facilitating and capturing knowledge inputs, or for transferring these inputs between provincial and national levels. There was also no further consultation regarding priorities identified for implementation prior to finalisation of the policy, with participants highlighting concerns about policy implementation at local levels as a result. This represents a lost opportunity for greater involvement of service users in policy development. CONCLUSIONS: Together with poor service-user representation, the format of the consultation process limited participant interaction and the possibility for engagement with, or uptake of, more experiential forms of knowledge. Several procedural elements were found to limit the elicitation and transference of consultation contributions for uptake into policy. Recommendations for future policy consultations include adapting the format of participatory processes to enable optimal use of participant knowledge, as well as greater service-user participation.