Half the patients with mild cognitive impairment (MCI) will develop dementia over a four-year period. The scientific literature was searched and analysed for predictors of rapid decline (MCI-plus) in patients with MCI. The most important predictors of fast cognitive deterioration were found to be: old age, previous rapid decline, severity and multiplicity of cognitive deficits, somatic co-morbidity, vascular and Alzheimer-type changes in the brain, Alzheimer-type cerebrospinal fluid findings and apolipoprotein E4 polymorphism. Many patients with MCI suffer from anxiety, depression or apathy and subtle, but subjectively significant, difficulties in the activities of daily living. It is concluded that MCI-plus offers a window for medical and psychological prophylaxis and rehabilitation.