Purpose : The purpose of this study was to review the clinical and mammographic findings of pure mucinousbreast carcinoma. Materials and Methods : In ten patients diagnosed as suffering from pure mucinous breastcarcinoma, we reviewed the clinical and mammographic findings. They were aged between 36 and 72(mean 46.3)years;nine were female and one was male. To describe breast mass, we used the terminology of the BreastImaging-Reporting and Data System developed by the American College of Radiology. Results : All patients hadpalpable masses. The long-axis diameter of the tumors was between 1.0 and 7.0(mean, 2.81)cm, and in two patients,tumors were multiple. No cases involved metastatic axillary lymph nodes. During the follow-up period of 2 to78(mean, 36.3) months, no patient died. Mammographic findings included lobular circumscribed masses in fourpatients, round or oval circumscribed masses in three a lobular microlobulated mass in one, a round microlobulatedmass in one and a round spiculated mass in one. Microcalcifications were noted in two cases. Architecturaldistortion and nipple retraction were each found in one patient. Conclusion : On mammography, pure mucinous breastcarcinoma was most commonly seen as a lobular or round circumscribed mass; these masses were palpable and clinicalprognosis was relatively good.