Objective To explore the expression of Bmi-1 and caspase recruitment domain-containing protein 9 (CARD9) in breast cancer tissues and their correlation with lymph node metastasis and prognosis. Methods A total of 96 breast cancer patients between January 2017 and November 2018 were enrolled as the research objects. The expression of Bmi-1 and CARD9 in breast cancer tissues and para-carcinoma tissues was detected. And their relationship with clinical pathology and prognosis was analyzed. Results The positive expression rates of Bmi-1 and CARD9 in breast cancer tissues were higher than those in para-carcinoma tissues (P＜0.05). The proportions of patients with TNM staging at stage Ⅲ and Ⅳ, histological grading at grade Ⅲ, long diameter of tumor not shorter than 2 cm, lymph node metastasis and ER+in Bmi-1 positive-expression group were higher than those in Bmi-1 negative-expression group. The proportions of patients with TNM staging at stage Ⅲ and Ⅳ, long diameter of tumor not shorter than 2 cm and lymph node metastasis in CARD9 positive-expression group were higher than those in CARD9 negative-expression group (P＜0.05). TNM staging at stage Ⅲ and Ⅳ, long diameter of tumor not shorter than 2 cm and lymph node metastasis were risk factors of Bmi-1 expression, while TNM staging at stage Ⅲ and Ⅳ and lymph node metastasis were risk factors of CARD9 expression (P＜0.05). There was no significant difference in 1-year survival rate among patients with different Bmi-1 and CARD9 (P＞0.05). AUC values of Bmi-1 and CARD9 in breast cancer tissues for predicting 1-year survival were 0.561 and 0.628, respectively.Conclusion The positive expression rates of Bmi-1 and CARD9 in breast cancer tissues are relatively high, and their positive expression is related to lymph node metastasis and TNM staging, while the expression of Bmi-1 and CARD9 is not significantly related to the survival at 1 year after surgery.