Two cases of F-FDG PET in developmental venous anomaly (DVA) with visual impairment were examined. Plain MRI could not determine the cause of visual symptoms; a contrast-enhanced CT scan showed the existence of DVA without apparent parenchymal damage due to infarction or hemorrhage. F-FDG PET revealed that the hypometabolic area extended to the visual tract, thus explaining the association between the visual impairment and DVA. F-FDG PET is therefore a useful tool for the evaluation of symptomatic DVA.