Background: Neuropsychiatric symptoms (NPS) often occur in patients with dementia. Understanding the course of NPS in dementia is important for healthcare professionals for psycho-educational purposes and adequate and timely interventions to prevent or diminish NPS as much as possible. Methods: We conducted a systematic literature search in several electronic databases. We combined search strings for the terms dementia, community-dwelling, cohort studies and NPS. Screening titles and abstracts, assessing the methodological quality and data-extraction were independently conducted by at least two authors. Results: This literature search revealed 6605 unique records of which 23 studies were included in data synthesis. In total 7184 patients participated in the included studies with a mean number of 312. Sixty percent of the participants were female and the mean age of all participants was 74.8 years. Follow-up varied between 1 and 6 years; in 17 studies loss to follow-up was less than 20% per year. NPS are highly prevalent, incident and persistent although frequency parameters vary considerably across studies. Delusions/delusional misidentification, wandering/agitation, aberrant motor behavior/motor hyperactivity and apathy are the most common NPS. For hallucinations, delusions/delusional misidentification, paranoia, aggression, wandering/agitation, aberrant motor behavior/motor hyperactivity, disinhibition, apathy, and sleep disturbance increasing trends in point prevalence rates have been found. Conclusions: NPS in community-dwelling patients are frequent and persistent. The increasing trends of several NPS in the course of dementia require a preventive approach of professional caretakers. For such an approach, a timely diagnosis and adequate professional support to prevent or diminish these problems is necessary.