Background: Pharmacists who are integrated into the ward team are involved in initial decision making, therefore pre-empting pharmaceutical problems and optimising therapy from the outset. Identifying the barriers and facilitators (determinants) to successful pharmacist integration within a multidisciplinary ward team will facilitate design of strategies to support integration. Objective: The study aimed to identify the modifiable barriers and facilitators to pharmacist integration into the ward-based multidisciplinary team. Method: Searches were conducted in May 2018 across 5 databases: MEDLINE, Embase, CINAHL, PsychINFO and ASSIA, combined with grey literature and manual searches. Qualitative and mixed-methods studies using a qualitative method of data collection and analysis were eligible if reporting at least 1 modifiable determinant. Framework synthesis using the Theoretical Domains Framework (TDF) as the a priori coding framework was undertaken. Behaviour change techniques for addressing the identified determinants were selected. Results: Twenty studies were included indicating 9 facilitators and 5 barriers to pharmacist integration. These were grouped into 3 themes. Professional knowledge and skills of the pharmacist were a facilitator to integration; interpersonal skills and relationships when representing positive interactions with team members were a facilitator whilst hierarchy was a barrier; working patterns were a facilitator when pharmacists were co-located with team members whilst profession-specific goals and excessive workload were barriers. These mapped to the TDF domains ‘knowledge’, ‘social/professional role and identity’, ‘skills’, ‘reinforcement’, ‘social influence’, ‘goals’, and ‘environmental context and resources’ respectively. Conclusion: The identified determinants within TDF domains and their associated behaviour change techniques now enable researchers to design theory- and evidence-based interventions to facilitate pharmacist integration into the ward-based multidisciplinary team. Pharmacist integration is facilitated by their knowledge and skills being valued and through demonstrating effective interpersonal skills. Re-structuring pharmacist responsibilities and working patterns to align with those of multidisciplinary team members also promotes integratio