Objective: To measure the levels of KLK6 and CA125 tumor marker and compare them as a predictor of epithelial type ovarian malignancy. KLK6 and CA125 were taken from blood serum of 60 ovarian tumor patients who met the inclusion criteria in consecutive sampling. CA125 quantitative examination and KLK6 titer were performed by ELISA. Surgical tissue from Dr. Soetomo Hospital, Surabaya was examined histopathologically at the Anatomical Pathology Laboratory of the Faculty of Medicine Airlangga University, Surabaya. Methods: This study is a diagnostic test using a cross-sectional design with a total sample of 60 ovarian tumor patients from obstetrics and gynecology outpatient clinic, Soetomo Hospital, Obstetrics and Gynecology Department, Faculty of Medicine, Airlangga University, Surabaya. CA125 was examined by ELISA, while KLK6 was examined using an ELISA reagent kit from Enzo Life Sciences Inc., USA. Results: This study examined a total sample of 60 patients, 30 patients (50%) with benign ovarian tumors, 26 patients (43.33%) with stage I ovarian cancer and 4 patients (6.66%) with stage II ovarian cancer. The best cut off for KLK6 is 3.14ng/mL and the standard CA125 cut-off is 35U/mL. The sensitivity and speciﬁcity of Ca125 are 70.00; 33.33, the sensitivity and speciﬁcity of KLK6 are 50.00; 100.00, PPV and NPV of Ca125 are 51.22; 52.63, PPV and NPV of KLK6 are 100.00; 66.67. Conclusion: KLK6 showed high speciﬁcity for the diagnosis of ovarian cancer. This can improve the diagnostic accuracy of Ca125 which has high sensitivity but low speciﬁcity. A combined panel of Ca125 and KLK6 showed high diagnostic efﬁciency for early-stage ovarian cancer.