The components of peer assisted learning (PAL) in the practice setting have not been previously defined, since research has hitherto focussed on outcomes, rather than construction. Whilst socio-cognitive and sociocultural development theory underpins the development of PAL in both the classroom and practice context, learner choice and flexibility are more evident in the latter: activities are selected by the learner and their student peer, according to personal preference and context, usually without tutor supervision or prior scripting. These are more akin to workplace learning practices than to the classroom. Drawing on data from a triple phased, flexible research design (comprising qualitative interviews, a collective case study and two Q-method studies with undergraduate physiotherapy students from a range of programmes), the activities, behaviours and perceptions of students engaged in PAL in the practice setting are presented in three themes. Companionship casts the peer as a buddy and ally, who helps create a supportive, emotional landscape that prepares for, and sustains, learning. In Collaboration, as learning partners, peers engage in a range of dialogic and activityorientated behaviours which mediate learning through processes of construction and co-construction. In Contrast, peer relationships are enacted according to issues of comparison, competition and conflict. The range of activities and behaviours involved in PAL in the practice setting are consistent across clinical areas, level of student and type of programme. Most students value PAL highly, and successful partnerships are enabled by factors that include mutual trust, respect, compatibility and a commitment to negotiating the shared learning experience. This research contributes new knowledge by extending the application of extant theory, providing a new framework by which PAL in the practice setting may be identified, and a taxonomy that describes its roles and activities. This will inform and prepare academics, clinicians and students engaging in practice-based PAL, and will provide both a foundation for its broader application, and a baseline for further research.