BACKGROUND: Preoperative evaluation of sentinel lymph nodes is very important in breast cancer patients. This study aimed to explore factors affecting the result of preoperative percutaneous contrast-enhanced ultrasound for sentinel lymph nodes (SLN-CEUS) using Sonovue. METHODS: A total of 176 patients with breast cancer who underwent preoperative SLN-CEUS to trace axillary sentinel lymph nodes were included. The positive result of SLN-CEUS was defined as both lymphatic vessels and SLN visible. The negative result was defined as the visible lymphatic vessels but the SLNs invisible, and neither lymphatic vessel nor SLNs invisible. Clinical features, histopathology, ultrasound features and doses of contrast agents were analyzed between the positive and negative groups. RESULTS: The diagnostic sensitivity, specificity, and accuracy of SLN-CEUS were 81.5%, 90.7%, and 87.8% respectively. The false negative and false positive rates were 18.5% and 9.3%. Age, distance from the anterior edge of the mass to the body surface (DTS), tumor location, pathologies and lymph nodes metastasis were significantly correlated with the results of SLN-CEUS between the negative and positive groups (P=0.032, 0.035, 0.036, 0.047 and <0.001). Logistic regression showed that age, location, DTS, and lymph node metastasis were independent factors influencing negative SLN-CEUS. CONCLUSIONS: In conclusion, independent factors affecting negative results of SLN-CEUS were lymph node metastasis, age, tumor location and DTS.