Abstract: Background Young people with congenital heart disease (CHD) are frequently affected by discontinued follow-up when transferring from paediatric to adult care. Identified predictors for discontinuation include mostly patient-related factors, and further knowledge of hospital and healthcare system factors is needed.Aim This study aims to explore patient-related, hospital-related and healthcare system-related factors affecting continued follow-up care after transfer, as perceived and experienced by paediatric cardiology and adult CHD (ACHD) healthcare providers (HCPs) in Sweden and Belgium.Methods This descriptive qualitative study included individual interviews with cardiologists, nurses and administrative staff, subjected to qualitative content analysis. A total of 30 HCPs from 13 specialist care outpatient clinics at 8 different centres in Sweden and Belgium were interviewed. HCPs were included if they had direct contact with patients and had at least 1 year of work experience.Findings The findings illuminate three main categories of factors perceived by HCPs to affect continued follow-up care after transfer, including 'care structure', 'care processes' and 'patient characteristics and circumstances'. Success was described as multifactorial, emphasising processes and structures of care, with a focus on collaboration, organisation, joint responsibility, resources, care relationships and transitional care interventions. Few differences appeared between paediatric and ACHD HCPs and between Swedish and Belgian HCPs.Conclusion HCPs perceived factors on patient, hospital and healthcare system levels to influence continued follow-up. Process-related and structure-related aspects of care were perceived as more influential than individual patient characteristics. Hence, future research on discontinued follow-up care should focus on process-related and structure-related aspects of care delivery.