Traditionally, all carcinomas arising from the surface epithelial layer of the ovary have been grouped together. This grouping has led to a single therapeutic strategy that is used for all epithelial ovarian cancers. However mucinous cancers appear to be distinct from serous cancers in their clinical behaviour and molecular signatures. In comparison to serous tumours, early stage mucinous tumours tend to be localised at diagnosis with a higher overall survival. But when metastatic at presentation or after recurrence, the outcome of mucinous tumours is far inferior to serous tumours. With standard platinum based chemotherapy the response rate and survival is far worse in mucinous cancers. The precise biological and molecular explanation for this difference remains unanswered. There is urgent need for testing and adoption of therapeutic approaches tailored to molecular characteristics of mucinous carcinomas so that patient survival can be optimised. Traditionally, all carcinomas arising from the surface epithelial layer of the ovary have been grouped together. This grouping has led to a single therapeutic strategy that is used for all epithelial ovarian cancers. However mucinous cancers appear to be distinct from serous cancers in their clinical behavior and molecular signatures. In comparison with serous tumours, early stage mucinous tumors tend to be localized at diagnosis with a higher overall survival. But when metastatic at presentation or after recurrence, the outcome of mucinous tumours is far inferior to serous tumours. With standard platinum based chemotherapy the response rate and survival is far worse in mucinous cancers. The precise biological and molecular explanation for this difference remains unanswered. There is urgent need for testing and adoption of therapeutic approaches tailored to molecular characteristics of mucinous carcinomas so that patient survival can be optimized.