Background Recruitment of pregnant or postnatal women and young families into health research is a challenge. Community midwives and health visitors are well placed to invite service users to participate, but evidence suggests that they do not always invite all potentially eligible service users. Our aim was to use the Theoretical Domains Framework to explore health visitors’ and community midwives’ perceived barriers and enablers to approaching service users about participation in research and to use the Behaviour Change Wheel to suggest theory-based strategies to improve future recruitment. Methods Health visitors and community midwives working in four NHS Trusts and one community partnership in England were invited to complete an anonymous, online survey. The sample comprised health visitors (n=39) and community midwives (n=22). Qualitative data from open-ended questions about recruitment behaviour informed by the Theoretical Domains Framework were analysed using directed content analysis and inductive coding to identify salient Theoretical Domains Framework domains and specific barriers and enablers. Strategies to address these barriers and enablers were identified using the Behaviour Change Wheel. Results Six key Theoretical Domains Framework domains were identified as salient to service user approach: (a) environmental context and resources; (b) social/professional role and identity; (c) social influences; (d) goals; (e) beliefs about capabilities; (f) knowledge. Intervention strategies were identified to address specific barriers (insufficient time and staff capacity, inadequate study materials, rejection of the study’s relevance to practitioners’ role, negative influence of researchers and managers, and competing priorities) and to leverage specific enablers (additional staff resource, the relevance of service user approach to professional role, positive influence of team members, managers and researchers, and a belief in the link between service user approach and improvements in healthcare). Conclusions This study provides new insights into why community midwives and health visitors do, and do not, invite service users to participate in research. Using the Theoretical Domains Framework and the Behaviour Change Wheel we identified that resourcing and social support for staff together with education and communication about the health benefits of approaching service users about research participation are key to improving research recruitment involving these health professionals.