The application of implementation research theory can identify factors that impact the successful implementation of new clinical interventions and highlight areas for further enhancement to improve intervention accessibility and sustainability. AIM AND METHOD: We aim to understand the perceived barriers and enablers identified by stakeholders toward the implementation of an upfront screening service identifying patients with dihydropyrimidine dehydrogenase (DPYD) gene variants as part of a feasibility study. DPYD variants can predispose patients to increased toxicity when exposed to fluoropyrimidine (FP) chemotherapies (capecitabine and 5-fluorouracil). Semi-quantitative questionnaires were circulated to stakeholders; medical oncologists, oncology trainees, pharmacists and nurses involved in the care of oncology patients in both inpatient and outpatient capacities. Data was collated and analysed by two independent assessors, utilising the Theoretical Domains Framework identify common themes. RESULTS: 30 stakeholders participated across four sites within Hunter New England and Central Coast Local Health Districts. Data saturation was estimated at ~60%. Domains include: Knowledge (Barriers: lack of awareness of recent data supporting use/ availability of testing); Social and Professional Role (Enablers: interest in reducing toxicities for patients); Belief about Consequences/ Capabilities (Barrier: questioning the effectiveness in reducing health utilisation while maintaining efficiency; Enablers: interest in trials, innovation and health service improvement, enthusiasm to be early adopters of new interventions); Environmental Context and Resources (Barriers: wait time for results, lack of infrastructure and accessibility of guidelines; Enablers: availability of internationally recommended guidelines). CONCLUSION: Intuitively, some barriers and enablers typically showed an inverse relationship. Factors identified within this study are similar to those identified in international studies focused toward DPYD genotyping, although we acknowledge the limited data within this realm. Themes identified will form the foundation for strategy development to be implemented alongside a larger scale clinical trial prospectively evaluating DPYD genotype-guided FP-dosing and toxicities and cost-effectiveness within the Australia health care system.