BackgroundSocial prescribing (SP) involves linking patients in primary care with services provided by the voluntary and community sector. Despite growing interest within NHS primary care, it remains unclear how and under what circumstances SP might contribute to good practice.AimTo define ‘good’ practice in SP by identifying context-specific enablers and tensions. To contribute to the development of an evidence-based framework for theorizing and evaluating SP within primary care.Design and settingRealist review of secondary data from primary care-based SP schemes.MethodWe searched for qualitative and quantitative evidence from academic articles and grey literature following the Realist and Meta-narrative Evidence Syntheses-Evolving Standards (RAMESES). We characterised common SP practices in three settings (general practice, link workers and community sector) using archetypes which ranged from best to worst practice.ResultsA total of 140 studies were included for analysis. We characterised common SP practices in three settings (general practice, link workers and community sector) using archetypes which ranged from best to worst practice. We identified resources influencing the type and potential impact of SP practices and outlined four dimensions in which opportunities for good practice arise: 1) individual characteristics (stakeholder’s buy-in, vocation, knowledge); 2) interpersonal relations (trustful, bidirectional, informed, supportive, transparent and convenient interactions within and across sectors); 3) organisational contingencies (the availability of a predisposed practice culture, leadership, training opportunities, supervision, information governance, resource adequacy and continuity and accessibility of care within organisations); and 4) policy structures (bottom-up and coherent policymaking, stable funding and suitable monitoring strategies). Findings where synthesised in a multi-level, dynamic and usable SP Framework.ConclusionOur realist review and resulting framework revealed that SP is not inherently advantageous. Specific individual, interpersonal, organisational and policy resources are needed to ensure SP best practice in primary care.