Abstract: Objective To explore the value of ultrasound and serum levels of CA125 in ovarian cancer diagnosis. Methods A consecutive series of 113 patients with ovarian tumor treated between October 2012 and December 2013 were analyzed. Patients included 53 cases of malignancy and 60 cases of benign tumors; all were diagnosed based on ultrasound and serum levels of CA125 one week before surgery，and then definitively diagnosed based on postoperative pathology. To adjust for baseline differences between the two groups， propensity-score matching was used to generate 34 pairs of patients. Results Serum CA125 assay showed the following diagnostic performance：sensitivity，88.2%；specificity，61.8%，PPV，69.8%；NPV，84.0%；and accuracy，75.0%. The corresponding values for ultrasound were 85.3%，88.2%，87.9%，85.7% and 86.8%. The corresponding values for the combination of serum CA125 assay and ultrasound were 94.1%，64.7%，72.7%，91.7% and 79.4%. Ultrasound alone showed significantly higher specificity than either serum CA125 alone or the combination of both methods（P＜0.05）. However，sensitivity，PPV，NPV and accuracy were similar across all three diagnostic methods（P＞0.05）. Conclusion Combining ultrasound with serum CA125 assay does not improve diagnostic accuracy.

Key words: Ovarian neoplasm, Ultrasound, Serum CA125 assay