NHS England’s Long-Term Plan for Mental Health highlights need to develop PNMH services and train staff ensuring service user involvement [1]. Women experiencing PNMH disorders often initially present to non-specialist healthcare professionals (NSHCP), meaning that they need specific training in assessment and management of PNMH disorders. A co-produced and co-facilitated simulation-based training programme in perinatal mental health was developed in 2019 by Sussex Partnership Specialist Perinatal Service in conjunction with University Hospital’s Sussex Simulation team. Primary Aim: Evaluate self-reported changes in confidence and competence of learners attending perinatal mental-health (PNMH) simulation training across multiple domains relating to assessment and management of PNMH problems. Secondary Aims: Evaluate impact of service user co-facilitation on PNMH simulation training; Assess whether participant demographics reflect training’s target professional groups. Service User Consultants (SUCs) were employed as faculty members and trained in simulation facilitation alongside professional faculty. Scenarios were developed in a multidisciplinary workshop, and aligned to the Health Education England (HEE) Competency framework in PNMH. Courses were co-facilitated by a Perinatal Psychiatrist and SUC. Data on participants’ confidence and knowledge across the competency framework domains was collated using a survey monkey questionnaire, pre and post-course. 242 responses were collected from participants from more than ten different staff groups e.g. junior doctors, (18%), health visitors (17%) & midwives (26%). Participant confidence improved significantly across all training domains. 93.5% of participants graded contribution of SUCs either useful or very-useful. 99.2% found the simulation training useful or very-useful, with all participants agreeing their future practice would consequently change. The simulation-based training programme increased confidence and understanding of NSHCPs from across the PNMH care pathway, on a number of domains set by HEE PNMH competency framework. Participants were overwhelmingly in support of SUC involvement in the provision of valuable training which resembled real-life clinical encounters via scenarios.