Aim: This article explores the delivery of trauma-informed residential treatment, focussing on factors that affect how it is provided by staff and received by clients, particularly the challenges encountered. Methods: Semi-structured qualitative interviews were conducted with stakeholders (n = 3), staff (n = 15) and clients (n = 19) of a women-only trauma-informed residential rehabilitation service in the UK. Interview data were systematically coded and analysed using iterative categorisation (IC). Findings: Trauma-informed treatment delivery was affected by: “recruiting and retaining a stable and trained staff team”; “developing therapeutic relationships and working with clients”; and “creating and maintaining a safe and stable residential treatment environment”. Clients’ complex needs and programme intensity made trauma-informed working demanding for staff to deliver and for clients to receive. Staff working in the residential service needed sufficient training, support and supervision to work with clients and keep themselves safe. Clients required safety and stability to build trusting relationships with staff and engage with the treatment. Conclusions: Trauma-informed residential treatment seems a valuable way of working with women with co-occurring substance use and trauma. However, it is challenging to deliver and likely to require significant resource investment. These findings appear relevant given increasing international interest in trauma-informed approaches within the addictions.