From its inception, the social work profession evolved in tandem with public health, and has historically contributed to public health efforts to restore, protect and promote public health principles. In recent times, however, the most prominent role for health-related social work is in hospital-based, multidisciplinary teams. Curiously, scant attention has been paid to the place of social workers’ knowledge—their ‘epistemic contribution’—within this medical context. This article reports the findings of a scoping review that examined the role and function of social work knowledge in healthcare teams. Thematic analysis of the literature revealed four key themes: (i) a lack of clarity and visibility—‘Ok, what is my role?’; (ii) knowledge Hierarchies—‘Jack of all trades and master of none’?; (iii) mediator and educator—‘Social work is the glue’ and (iv) public health principles—‘We think big’. Findings show that despite social work’s epistemic confidence, and alliance with broader public health principles and aims, its knowledge can be marginalised and excluded within the multidisciplinary team context. The article introduces Fricker’s theory of ‘Epistemic Injustice’ as a novel framework for inquiry into health care teams, and the mobilisation of social work knowledge within them.