To describe the provision of evidence-based psychological therapies for the treatment of psychosis in a large Australian mental health service; and to explore the barriers and facilitators to providing these therapies. Mixed-methods study including: 1) a retrospective audit of 100 clients with schizophrenia spectrum disorder to estimate adherence to guideline recommended psychological therapies; and 2) a cross-sectional survey of community based mental health practitioners, based on the Theoretical Domains Framework, to understand the barriers and facilitators to delivering psychological therapies to clients with psychosis. Twenty-five percent (25/100) of the audited sample engaged with psychological services. Of those who did, two received the recommended dose of evidence-based therapy. Thirty-three percent (37/112) of mental health practitioners completed the survey. Barriers to the delivery of psychological therapies related to perceived lack of knowledge, skills, and confidence with the therapies, and beliefs about who will (and will not) benefit. Other barriers included lack of time, demanding caseloads, and a culture of risk and crisis management. People with psychosis have poor access to evidence-based psychological therapies. The barriers to providing psychological therapies are multifactorial and should be systematically addressed to improve health and quality of life outcomes for people living with psychosis. Abbreviations: CBT: Cognitive behaviour therapy; CBTp: cognitive behaviour therapy for psychosis; CRT: cognitive remediation therapy; FIp: family intervention for psychosis; PORT: Patient Outcomes Research Team; RANZCP: Royal Australian and New Zealand College of Psychiatrists; NICE: UK National Institute of Clinical Excellence; TDF: The Theoretical Domains Framework; HoNos: Health of the Nation Scale; EBPIs: Evidence Based Psychological Interventions; ACT: Acceptance and Commitment Therapy. What is already known about this topic: Clinical practice guidelines for the past two decades have recommended psychological interventions be routinely offered to clients with psychosis. There exists a substantial and widely acknowledged evidence-practice gap concerning the implementation of evidence-based psychological interventions for psychosis within public mental health services. Despite knowledge of effective interventions, the translation into clinical practice continues to fall short. Barriers to the provision of evidence-based psychological interventions for psychosis are evident at various levels, including challenges among staff, service recipients and organisational culture. These factors collectively impede the translation of evidence-based psychological interventions into routine psychosis care. What this topic adds: Identifying and understanding local structural, cultural, resourcing, and attitudinal barriers, while emphasising enablers, becomes essential. This understanding forms the foundation for enhancing access to evidence-based psychological interventions, ultimately elevating the quality of care outcomes for people with psychosis. To foster equitable access and awareness of evidence-based psychological interventions for psychosis, initiatives such as increased staff training, service redesign emphasising the value of psychological interventions, improved referral processes, advocacy, role clarification for clinicians, and enhanced supervision opportunities are crucial. These multifaceted strategies collectively may contribute to a more informed and effective approach to evidence-based psychological interventions for psychosis, promoting optimism and treatment choice. Once local structural, cultural, resourcing, and attitudinal factors are recognised and understood targeted improvements in service delivery for psychosis can be strategically implemented, aligning with the unique dynamics of the local context and care setting. [ABSTRACT FROM AUTHOR]