ObjectivesIt is well known that Alzheimer's disease (AD)‐type pathology is commonly present in dementia with Lewy bodies (DLB) brains and that the degree of AD‐type pathology has an influence on the clinical characteristics of DLB. Although significant hypometabolism in the temporoparietal/precuneus on [18F]fluoro‐d‐glucose (18F‐FDG) positron emission tomography (PET) scans is considered to support a diagnosis of AD, some DLB patients also exhibit this metabolic pattern. The clinical significance of the metabolic pattern on DLB remains unknown. MethodsTwenty‐three DLB patients, 10 AD patients, and 11 controls underwent 18F‐FDG PET scans. According to the degree of hypometabolism in the parietal/precuneus regions, representing the AD‐like metabolic pattern, 12 patients were placed in the DLB‐AD(+) group and 11 patients were placed in the DLB‐AD(−) group. The demographics and clinical variables were compared among the four groups. ResultsIn addition to the parietal/precuneus regions, the DLB‐AD(+) group exhibited significantly greater posterior cingulate hypometabolism than the DLB‐AD(−) group, although occipital metabolism did not differ. The prevalence of visual hallucinations and extracampine hallucinations, and the Bender–Gestalt test score were significantly higher in the DLB‐AD(+) group than the DLB‐AD(−) group, although there were no differences in the demographics and other examined clinical variables between the two DLB groups. These clinical differences were absent in the DLB‐AD(−) group, AD group, and controls. ConclusionsParietal/precuneus hypometabolism may be associated with clinical characteristics in DLB patients. Further multiple imaging modalities that are sensitive to AD‐type pathology are needed to reveal the neurobiological basis of the AD‐like metabolic pattern. Copyright © 2014 John Wiley & Sons, Ltd.