Eighteen patients with the clinical diagnosis dementia of Alzheimer type (AD/SDAT) and 20 patients with the clinical diagnosis multiinfarct dementia (MID) were interviewed using a subscale to the Comprehensive Psychopathological Rating Scale (CPRS), consisting of items measuring psychopathological symptoms and signs commonly seen in patients with dementia. The aim of the investigation was to evaluate whether a difference in psychopathology between AD/SDAT and MID could be observed during a semistructured psychiatric interview using the CPRS. In both groups the duration of illness was similar and the dementia mild to moderate. All patients were subjected to somatic, psychiatric, laboratory, neurophysiologic and neuroradiologic examinations in order to obtain the correct clinical diagnoses. The results show that patients with AD/SDAT have a more variable psychopathology than patients with MID. Patients with MID were rated lower on all items used, especially those concerning verbal and personal contact. This might explain the generally accepted opinion that patients with MID have better contact with their surroundings and better preservation of their personality, even though they have the same degree of dementia as patients with AD/SDAT.