Background: In Germany, advance care planning (ACP) was first introduced by law in 2015. However, ACP is still uncommon in Germany and only few people have advance directive forms. This study aims to evaluate an ACP program in care dependent community-dwelling persons, compared to optimised usual care. Methods: A cluster-randomised controlled trial of 12 months duration will be conducted in 3 German study sites comparing the pretested ACP-counselling offered by trained nurses with a control group receiving optimised usual care. Using external concealed randomisation, 16 home care services each will be included in the intervention and the control group (30 participants per cluster; n = 960). Eligibility criteria for patients are: ≥60 years, somehow care dependent, adequate German language skills, assumed life-expectancy of ≥4 weeks, and cognitive ability for participation. ACP will be delivered by trained nurse facilitators of the respective home care services and communication will include proxy decision-makers. The primary endpoint will be patient activation, assessed by the Patient Activation Measure (PAM-13). Secondary endpoints include ACP-engagement, proportion of prepared advance directives, number and duration of hospitalisations, quality of life as well as depression and anxiety. Further, comprehensive economic and process evaluations will be conducted. Discussion: STADPLAN is the first study in Germany that assesses an adapted ACP intervention with trained nurses in home care services and the first international study focusing on cost effectiveness of ACP in community-dwelling older persons. The results will help to improve the understanding and communicating of patients' preferences regarding medical treatment and care and thereby contribute to patients' autonomy. Trial registration: German Clinical Trials Register: DRKS00016886 (Date of registration: 04.06.2019).