The aim of the present study was to examine the factors responsible for an early or late date for the diagnosis of dementia. In the course of our gerontopsychiatric outpatient department concerning impaired memory ("Gedächtnissprechstunde"), we examined four patients with cognitive impairments and explored their caregivers with regard to the biographic history and the course of the patient's disease. How can we describe the time course of identification and assessment of the symptoms of dementia by caregivers and the factors which are controlling this process from its retrospectively estimated beginning to the date of the first diagnosis of dementia? Concerning the caregivers' certainty in the field of interpretation fo symptoms we could separate for the first time four consecutive stages: First, the stage of undiscovered illness; second, the stage of insecurity; third, the stage of subjective certainty; fourth, the stage of objective certainty. Our case histories revealed that the phase of disease, the insight into one's disease, and the degree of suffering by the patient on the one hand, and the medical education, the setting of social roles and the degree of suffering by the caregivers on the other hand, are possible factors which control the time interval (1.25 to 11 years) between the retrospectively estimated beginning of the disease and the date of the first diagnosis. Is there any pattern of the patient's consultations with a physician and the doctor's diagnostic answers during the time course between the retrospectively estimated beginning of the disease and the date of the first diagnosis of dementia? In spite of periodical consultations of physicians, the opportunity for an early diagnosis was not achieved. Factors which influence this diagnostic process are believed to be the status quo of professional standards of quality and the general conditions in Public Health. In two cases it took two years until the physician decided to initiate a differential diagnostic process; in another case the medical recommendation in favor of differential diagnosis was declined by the patient for more than one year. Additionally, the present case reports clearly demonstrate that coping with the disease both by the patient and the caregivers can only start when the stage of objective certainty is reached. Considering ethical issues as the principle of autonomy, this may argue for a differential diagnosis of cognitive impairment and dementia as soon as possible.