We develop a practice-based framework of inter-organisational human resource management that puts multi-employer work arrangements in inter-firm networks at its centre. By reinterpreting existing knowledge on multi-employer work arrangements and how they are managed, we delineate four processes in the assemblage of inter-organisational HR management. To illustrate the usefulness of our framework, we explore the question of whether and how an inter-organisational HR management develops in four exemplary cases of multi-employer work arrangements. These cases reveal that the quality and degree of inter-organisational HR management varies considerably, also depending on whether worker representatives show network awareness and orient their activities towards inter-organisational relations.