Abstract: Objective To investigate the clinicopathological features and prognosis of mucinous breast carcinoma (MBC), and then compare it with invasive ductal carcinoma non-specific type (IDC-NOS). Methods we collected clinical data from 88 MBC patients and 210 IDC-NOS patients who were diagnosed in the Affiliated Hospital of Xuzhou Medical University from January 2008 to December 2017. Both groups were compared for patient age, tumor size, clinical stage, lymph node metastasis rate and immunohistochemical expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor-2 (Her-2) and prognosis. Results Among 88 MBC patients, there were 64 patients with pure mucinous breast carcinoma (PMBC) and 24 ones with mixed mucinous breast carcinoma (MMBC). The patients were 29-83 years old, with an average age of 56 years and a median age of 57 years. The total positive rates of ER, PR and Her-2 in 88 MBC cases were 94.3%, 85.2% and 27.2% respectively, with the lymph node metastasis rate was 31.8%. Compared with the MMBC group, the MMBC group presented remarkable decreases in the lymph node metastasis rate and clinical stage (P<0.01). Compared with the IDC-NOS group, the MBC group had a higher age and a lower lymph node metastasis rate. Based on immunohistochemical staining, the MBC groups showed that increased positive rate of ER and PR and decreased positive rate of Her-2, compared with the IDC-NOS group (P<0.05). The 5-year disease free survival (DFS) rate and overall survival (OS) rate in the MBC group were 88.8% and 98.6%, which however were not statistically different from those in the IDC-NOS group (85.4% and 95.5%, respectively, P>0.05). Conclusions MBC is a slow growing tumor with a low-grade malignancy. Compared with IDC-NOS, MBC has higher hormone expression, lower lymph node metastasis rate and better prognosis.