Background: The accuracy of intra-operative frozen section is very important in the evaluation of ovarian tumours so that appropriate surgical procedure can be selected.

Study Objective: To assess the sensitivity, specificity, positive predictive value and negative predictive value of intra-operative frozen section as compared to final histopathological result in ovarian tumours.

Materials and Methods: All patients underwent intra-operative frozen section for ovarian masses in Hospital Sultanah Bahiyah over 9 years duration from June 2008 till April 2017 were reviewed. Frozen section diagnosis and final histopathological reports were compared.

Results: A total of 94 cases were recruited for final evaluation. The frozen section diagnosis was comparable with the final histopathological reports in 85% of cases. The sensitivity, specificity, positive predictive value and negative predictive value for benign and malignant ovarian tumours were 95.7%, 88.9%, 90%, 95.2% and 75%, 99%, 90% and 91.8% respectively. Whereas, for borderline ovarian tumours, the sensitivity and specificity was 81 and 90% respectively; positive predictive value was 70.8% and negative predictive value was 94.1%.

Conclusion: The accuracy of intra-operative frozen for ovarian tumours is high and it remained a reliable option in assessing ovarian masses intra-operatively.