Two-third of XXX cardiovascular disease (CVD) risk management is delivered in primary care practices via integrated care programs. Although these programs calculate individual risk for cardiovascular patients, risk stratification to identify patients for prioritized recall is currently not implemented. Given the anticipated staffing shortages and the substantial heterogeneity in primary care patients at risk of CVD, there is a need for optimizing this approach and promoting proactive organization of care. We therefore developed a multilevel complex intervention (PROSPERA) and explored barriers and facilitators of the pilot version in an early phase of implementation. The PROSPERA program comprises: 1) population-level risk stratification, 2) individual-level clinical decision support tools and 3) remote patient monitoring.To explore anticipated and experienced barriers and facilitators by healthcare professionals when using the PROSPERA program in primary care.We conducted 4 focus groups and 6 interviews with 9 general practitioners and practice nurses focusing on barriers and facilitators in current cardiovascular risk management and anticipated and experienced barriers and facilitators when using the PROSPERA program. After verbatim transcribing, interviews were coded inductively. Constructs of the Theoretical Domains Framework (TDF) were used for thematic analysis.Barriers and facilitators on three healthcare professionals’ behaviours (providing proactive care, using clinical decision support tools and discussing outcomes) were found in 11 TDF-domains. Main barriers related to a lack of guidelines and know-how, pessimism on breaking habits, altered professional roles and limitations in technological infrastructure. Main facilitators related to beliefs about the value of proactive selection, the need for structural change, and optimism about clinical decision support tools contributing to improved comprehension, motivation and activation of patients.The PROSPERA pilot study adds to knowledge on barriers and facilitators in behaviour change of health care professionals when working with a complex intervention in primary care. To support further adoption of the PROSPERA program in clinical practice, healthcare professionals need further education and training, as well as support by restructuring the environment.The insights of this study will be used for developing implementation strategies for a cluster randomized clinical trial. Results of the trial are expected in 2028.