To identify the Doppler flow characteristics of benign ovarian tumors, and to compare the variables involved with those of normal ovaries during the follicular phase. Ninety-one women comprised the study group: 43 were recruited from patients undergoing surgical exploration because of adnexal masses, and the remaining 48 were asymptomatic volunteers with normal ovaries. The ovarian volume and morphology, location of the intratumoral and intraovarian arteries, pulsatility index (PI), resistance index (RI), peak systolic velocity, and minimum diastolic velocity were assessed with transvaginal color Doppler ultrasonography. We examined patients with adnexal tumors before surgery and asymptomatic volunteers during the follicular phase of their menstrual cycles. Arterial blood flow was detected in 49 (89%) of the 55 benign tumors and in 89 (94%) of the 95 normal ovaries. The PI was less than 1.0 in 80% of the benign tumors and 94% of the normal ovaries. The RI was less than 0.4 in 43% of the benign tumors and 25% of the normal ovaries. Blood flow exhibited a lower mean PI but a higher mean peak systolic velocity and minimum diastolic velocity value in benign tumors compared with normal ovaries. There were no differences in the Doppler characteristics of the benign tumors between the follicular and luteal phases. The blood flow in benign tumors and normal ovaries may have low PIs and RIs, even during the follicular phase. Therefore, low PIs and RIs alone should not be interpreted as pathognomonic signs of malignancy.