Background: Pure mucinous breast carcinoma is a relatively rare subtype of breast malignancy. This study is to investigate the clinical and pathologic features of pure mucinous breast carcinoma. Patients and Methods: A retrospective review of our database of patients who presented with breast cancer was performed. The medical records of 1,060 patients with invasive breast cancer who underwent surgery were reviewed. Results: 28 patients with pure nnucinous breast cancer were identified. The mean age was 55.28 +/- 15.73 years. 17 patients underwent modified radical mastectomy; 11 underwent breast-conserving therapy. The tumor size was T1 in 19 patients, T2 in 8 patients, and T3 in 1 patient. None of the patients had lymph node metastasis. There was no distant metastasis. 18 were stage I, and 10 were stage II. Estrogen receptor, progesterone receptor, HER-2, and P53 were positive in 96, 93, 0, and 28%, respectively. Median follow-up was 42 months (range 1-84 months). 1 patient had local recurrence. The overall survival rate was 100%. Conclusion: Pure mucinous breast carcinoma has a favorable prognosis. Less invasive treatment might be optional. Larger data samples with longer followup would be necessary to gain a better understanding of this disease.