Background: Despite a strong evidence base and policy recommendation supporting the implementation of psychoeducation interventions within the mental health system, equitable access for many service users and family members has not been achieved. To enhance translation, developing an evidence-base around the factors that influence implementation of interventions is critical. Methods: The aim of the study was to explore the factors influencing implementation of a group cofacilitated recovery focused psychoeducation intervention. The study design was explorative qualitative descriptive, involving the collection of data through individual and focus group interviews with key stakeholders (n = 75) involved with the implementation within 14 mental health sites in the Republic of Ireland. The Consolidation Framework for Implementation Research (CFIR) was used as a conceptual framework to guide data collection and analysis. Results: Key enablers and barriers were identified across all CFIR domains of the framework with some factors (depending on context) being both an enabler and a barrier. Important factors in the outer setting domain included structural stability within national systems and the peer payment system, while the extent of a recovery�oriented culture, leadership, implementation readiness, and buy-in were influential factors in the inner setting. The characteristics of the intervention in terms of design, evidence-base and adaptability also shaped the intervention’s implementation as did the knowledge, beliefs and self-efficacy of facilitators. In terms of processes, implementation was influenced by the degree of engagement of key individuals who championed and supported the programme. The results highlight that while some of the barriers were specific to the programme, many reflected systemic and structural challenges within health services more generally. Conclusion: Findings from this study provide an enhanced understanding of the different layers of determinants to implementation of an intervention. Overcoming challenges will involve positive and ongoing engagement and collaboration across the full range of stakeholders that are active within each domain, including policy and operational levels. The quality of leadership at each domain level is of crucial importance to successful implementation. Keywords: Implementation science, Barriers, Enablers, Psychoeducation, Mental health services, Framework analysis, Consolidation framework for implementation research