To assess prospectively a logistic model based on sonographic morphologic and color Doppler findings, which had been developed to predict adnexal malignancy, 167 consecutive and unselected patients (mean age, 45.7 yr; range, 17 to 81 yr; 113 [67.7%] premenopausal and 54 [32.3%] postmenopausal) diagnosed as having an adnexal mass and scheduled for surgery were prospectively included in this study. All patients were evaluated by transvaginal color Doppler ultrasonography. The probability of adnexal malignancy was estimated prior to surgery, applying a logistic model developed previously. A probability of malignancy greater than 75% was considered to assess model performance. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated for the model. In all cases definitive histopathologic diagnosis was obtained. One hundred and twenty-five (74.9%) benign and 42 (25.1%) malignant tumors were found. The sensitivity, specificity, positive predictive value, and negative predictive value of the model were 85.7% (95% confidence intervals, 71.4% to 94.6%), 100% (95% confidence intervals, 97.1% to 100%), 100% (95% confidence intervals, 90.3% to 100%), and 95.4% (95% confidence intervals, 90.3% to 98.3%), respectively. Overall accuracy was 96.4% (95% confidence intervals, 91.3% to 98.7%). Our results confirm the validity of the proposed logistic model in predicting adnexal malignancy.