The authors report their experience with the color Doppler study of the prostate in a series of 1,075 transrectal US exams performed September 1991 to June 1992. US-guided biopsy was performed in 82 patients; histopathology confirmed the diagnosis in 32 cases. Color-Doppler US provided accurate blood vessel mapping in the normal gland. As for benign prostate conditions, color-Doppler features definitely helped a diagnosis to be made, especially in nodular hyperplasia. Carcinomas usually exhibited marked and inhomogeneous increase in the vascularization of peri- and intralesional areas. This feature was especially valuable in isoechoic carcinomas where US is known to exhibit limitations. The authors suggest that the integration of clinical, laboratory and US with color-Doppler findings allows higher diagnostic accuracy.