Prostatic atrophy may be histologically and at ultrasound similar to adenocarcinoma causing diagnostic confusion, its frequency increases with age but the etiopathogenesis is unknown. Based on a systematic study in autopsies previously done by one of us, ischemia due to local intense arteriosclerosis seems to be a potential factor for its pathogenesis. Absent blood flow in areas of prostatic atrophy might be a further evidence for a possible role of ischemia. From a total of 298 patients biopsied and studied by gray-scale and color Doppler transrectal ultrasound in the period 1998 to 2001, 33 patients had suspicious lesions (37 hypoechoic nodules and 3 heterogeneous lesions) showing prostatic atrophy as the only diagnosis on all these biopsied lesions. Adenocarcinoma, high-grade intraepithelial neoplasia or other atypical lesions were absent in all patients. On color Doppler the suspicious areas showed absent flow in 24/40 (60%), present flow in 12/40 (30%), and increased flow in 4/40 (10%) of the lesions. Absent flow in the majority of the lesions studied may be a further evidence for a possible role of local ischemia in the etiopathogenesis of prostatic atrophy.