Transvaginal Doppler ultrasound was applied to 85 patients to determine whether pelvic malignancy could be predicted by pulsatility (PI) and resistive indices (RI) of intratu-moral, ovarian, and uterine vessels. Thirty-five of the patients in the study were confirmed to have malignant tumors of the cervix, uterus, or ovary. The mean intratu-moral PI and RI from malignant tumors were 0.81 (SD 0.24; range 0.3-1.2) and 0.54 (SD 0.10; range 0.27-0.62), respectively. They were significantly lower than those of the benign group (both with P < 0.05, Studentʼs t test). Thresholds of intratumoral PI < 1.0 and RI < 0.6, which differentiate malignant from benign tumors, were determined by using two receiver operating characteristic (ROC) curves. These gave a sensitivity of 94% and specificity of 63% for PI and a sensitivity of 71% and specificity of 63% for RI. The mean PI and RI from individual ovarian and uterine vessels were also significantly lower for the malignant group than those for the benign group. The authors conclude that PIs and RIs from intratumoral, ovarian, and uterine vessels are all useful in differentiating malignant tumors from benign ones, but universal thresh-olds for this purpose are far from determined. Also, comparison of intratumoral PI and RI showed that neither PI nor RI was statistically better than the other in malignancy prediction, because the areas under the two ROC curves were not statistically different (P > 0.2, chi-square method).