We evaluated the ability of MRI of the amygdala to diagnose early Alzheimer's disease (AD). The volume of the amygdala was measured in 54 patients with probable AD, 38 subjects with age-associated memory impairment (AAMI), 34 cognitively normal elderly controls (OC) and 20 young controls (YC). The amygdala was atrophied in all the elderly study groups with atrophy being strongest in the AD group (p < 0.0001). The OC and AAMI groups differed from the YC group (p < 0.05) but not from each other. There was a major overlap between the study groups. The volumes also correlated with age (p < 0.0001) and gender (p < 0.001). A correct classification was achieved in 74% of AD patients and the non-demented elderly subjects. Thus, MRI of amygdala fails to diagnose AD accurately.