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. National policy; structural stability with national systems; leadership at all levels; peer payment system; local champions and support from multidisciplinary team members; evidence strength and quality of the programme design; availability of resources; referral pathways; knowledge, beliefs and self-efficacy of facilitators, as well as local culture influenced implementation. While some were specific to the programme, many barriers 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.