Background: Both neuropsychiatric symptoms (NPS) and psychotropic drug use (PDU) are common in institutionalized People with Young Onset Dementia (PwYOD) and can produce negative outcomes such as reduced quality of life and high workload. In community-dwelling PwYOD, NPS are found to be associated with unmet care needs. This emphasizes the importance of a care program for the management of NPS in institutionalized PwYOD that also addresses unmet care needs and PDU. The objectives of the Behavior and Evolution of Young ONset Dementia part 2 (BEYOND-II) study are to develop a care program for the management of NPS in institutionalized PwYOD and to evaluate its effectiveness. Methods: The care program consists of an educational program combined with an intervention to manage NPS with the following five steps: the evaluation of psychotropic drug prescription, detection, analysis (including the detection of unmet needs), treatment and the evaluation of NPS. A stepped wedge design will be used to evaluate its effectiveness. The primary outcomes are agitation and aggression and other NPS. The secondary outcomes are PDU, quality of life, the workload of nursing staff and job satisfaction. Additionally, a process analysis and a cost-consequence analysis will be conducted. Conclusions: The study protocol of the Beyond-II study describes the development, implementation and evaluation of a care program for the management of NPS in institutionalized PwYOD. This care program provides a structured method for the management of NPS, in which unmet needs and PDU are also addressed.