Objective The objective of this article is to examine the factors affecting the design, commissioning and delivery of integrated health and well-being services (IHWSs), which seek to address multiple health-related behaviours, improve well-being and tackle health inequalities using holistic approaches. Study design Qualitative studies embedded within iterative process evaluations. Methods Semi-structured interviews conducted with 16 key informants as part of two separate evaluations of IHWSs in North East England, supplemented by informal observations of service delivery. Transcripts and fieldnotes were analysed thematically. Results The study findings identify a challenging organisational context in which to implement innovative service redesign, as a result of budget cuts and changes in NHS and local authority capacity. Pressures to demonstrate outcomes affected the ability to negotiate the practicalities of joint working. Progress is at risk of being undermined by pressures to disinvest before the long-term benefits to population health and well-being are realised. The findings raise important questions about contract management and relationships between commissioners and providers involved in implementing these new ways of working. Conclusions These findings provide useful learning in terms of the delivery and commissioning of similar IHWSs, contributing to understanding of the benefits and challenges of this model of working.