This study explored the perceptions of staff in an interprofessional team based on a medical rehabilitation ward for older people, following the introduction of a service improvement programme designed to promote better teamworking. The study aimed to address a lack of in-depth qualitative research that could explain the day-to-day realities of interprofessional teamworking in healthcare. All members of the team participated, (e.g. nurses, doctors, physiotherapists, social worker, occupational therapists), and findings suggest that interprofessional teamworking improved over the 12-month period. Four themes emerged from the data offering insights into the development and effects of better interprofessional teamworking: the emergence of collegial trust within the team, the importance of team meetings and participative safety, the role of shared objectives in conflict management and the value of autonomy within the team. Reductions in staff sickness/absence levels and catastrophic/major patient safety incidents were also detected following the introduction of the service improvement programme.