INTRODUCTION: Systematic reviews demonstrate that advance care planning (ACP) has many positive effects for residents of aged care facilities, including decreased hospitalisation. The proposed Residential Aged Care Facility (RACF) 'Goals of Patient Care' (GOPC) form incorporates a resident's prior advance care plan into medical treatment orders. Where none exists, it captures residents' preferences. This documentation helps guide healthcare decisions made at times of acute clinical deterioration. METHODS AND ANALYSIS: This is a mixed methods study. An unblinded cluster randomised controlled trial is proposed in three pairs of RACFs. In the intervention arm, GOPC forms will be completed by a doctor incorporating advance care plans or wishes. In the control arm, residents will have usual care which may include an advance care plan. The primary hypothesis is that the GOPC form is superior to standard ACP alone and will lead to decreased hospitalisation due to clearer documentation of residents' medical treatment plans. The primary outcome will be an analysis of the effect of the GOPC medical treatment orders on emergency department attendances and hospital admissions at 6 months. Secondary outcome measurements will include change in hospitalisation rates at 3 and 12 months, length of stay and external mortality rates among others. Qualitative interviews, 12 months post GOPC implementation, will be used for process evaluation of the GOPC and to evaluate staff perceptions of the form's usefulness for improving communication and medical decision-making at a time of deterioration. DISSEMINATION: The results will be disseminated in peer review journals and research conferences. This robust randomised controlled trial will provide high-quality data about the influence of medical treatment orders that incorporate ACP or preferences adding to the current gap in knowledge and evidence in this area.