AIMS AND OBJECTIVES To describe whether an action research approach can be used to build capacity of residential aged care facility staff to support undergraduate nursing students' clinical placements in residential aged care facilities, using development of an orientation programme as an exemplar. BACKGROUND Aged care facilities are unpopular sites for nursing students' clinical placements. A contributing factor is the limited capacity of staff to provide students with a positive placement experience. Strategies to build mentor capability to shape student placements and support learning and teaching are critical if nursing students are to have positive placements that attract them to aged care after graduation, an imperative given the increasing care needs of the ageing population worldwide. DESIGN Action research approach employing mixed-methods data collection (primarily qualitative with a quantitative component). METHODS Aged care facility staff (n = 32) formed a mentor group at each of two Tasmanian facilities and met regularly to support undergraduate nursing students (n = 40) during placements. Group members planned, enacted, reviewed and reflected on orientation procedures to welcome students, familiarise them with the facility and prepare them for their placement. Data comprised transcripts from these and parallel student meetings, and orientation data from student questionnaires from two successive placement periods (2011/2012). RESULTS Problems were identified in the orientation processes for the initial student placements. Mentors implemented a revised orientation programme. Evaluation demonstrated improved programme outcomes for students regarding knowledge of facility operations, their responsibilities and emergency procedures. CONCLUSION Action research provides an effective approach to engage aged care facility staff to build their capacity to support clinical placements. RELEVANCE TO CLINICAL PRACTICE Building capacity in the aged care workforce is vital to provide appropriate care for residents with increasing care needs.