This thesis deals with routines for collaboration among specialists from different domains in healthcare. Healthcare policy is increasingly directed at transforming clinical healthcare into an interdisciplinary organization where diverse medical specialists collaborate in delivering complete treatments to the patient. However, as both practice and research repeatedly reports, achieving interdisciplinary collaboration is difficult. Due to the divides in knowledge and practice which exist between the medical disciplines, multidisciplinary clinics do not automatically lead to collaboration involving integration of disciplinary knowledge. Based on recent conceptualizations of organizational routines as sources of both stability and flexibility, this thesis concentrates on the type of routines that enable collaboration across domain boundaries. Collaboration routines, as they are called here, are suggested to support the interdisciplinary clinic in making use of its diversity in knowledge and practice. The thesis is comprised of four papers, including three empirical case studies of clinical healthcare. The combined findings indicate that collaboration routines support idea generation, testing of new joint practices and trial-and-error learning. Contrary to the common underlying conception of routines as blueprints, these findings bring to the surface an underlying logic of shared learning. Collaboration routines continuously support the formation and maintenance of shared cognition and shared motivation among different domain specialists, thereby assuming a function of continuous routinizing. The thesis contributes to the literature on routines by advancing research on how routines can support collaboration across domain boundaries within an organization.