Background: In the future, an increase in health care needs in the elderly is expected. Reports on unmet care needs of the oldest old with cognitive disorders are pending. This study aims at exploring unmet needs in the oldest old primary care patients with mild cognitive impairment (MCI) and dementia. Furthermore, the association between sociodemographic and clinical factors and unmet needs ought to be analyzed. Methods: Based on the study “Needs, Health Service Use, Costs and Health-Related Quality of Life in a Large Sample of Oldest-Old Primary Care Patients (85+)” (AgeQualiDe), 749 patients (unimpaired, MCI, and dementia) aged 85 years and older, their relatives (n = 421), and general practitioners (GPs) (n = 607) were assessed. Descriptive, inferential, and regression analyses were run. Results: Most unmet needs were observed in dementia patients, although needs were less frequently rated as unmet by dementia patients themselves as compared to relatives and GPs. Unmet needs were associated with MCI and dementia; other risk factors were age, education, and marital status. Conclusion: This study provides first data on unmet needs according to different perceptions in the elderly with MCI and dementia in Germany. Need assessments should be part of medical examinations to ensure a high-quality health care in the elderly.