Background: Little is known about diagnostic work-ups or the costs of diagnosing dementia in specialized care. Here, we analyzed the costs of diagnosing dementia according to specific dementia disorders. Methods: A prospective descriptive design was used to analyze the cost of diagnosing dementia for 120 patients with suspected dementia at a German memory clinic. The duration of clinical consultations and use of technical procedures were recorded by the memory clinic staff. To detect cost drivers, a multiple linear regression model was used.Results: Of patients with suspected dementia, 44% were diagnosed with dementia. The total cost per patient and diagnostic process amounted to 501 € across all patients and 659 € for patients who were diagnosed with dementia. The costs varied between 649 € for patients with Alzheimer's disease, 662 € for patients with vascular or mixed dementia, and 705 € for patients with unspecific dementia. A final diagnosis of dementia was the only factor that was significantly associated with the diagnostic cost (b = 356, CI -182, CI + 531, p = 0.001).