ObjectivesTo prospectively study the ultrasound-guided near-infrared diffuse optical tomography (DOT) findings of the total haemoglobin concentration (THC) detected in invasive breast carcinomas and its contribution to the prediction of axillary lymph node (LN) status. MethodsA total of 195 invasive breast carcinomas were prospectively studied with DOT before surgery. Lumpectomy or mastectomy with full axillary nodal dissection was performed. Tumour size and THC level were correlated with LN status by a logistic regression analysis. ResultsOne hundred twenty-four patients (63.59%) was LN(−) and 71 (36.41%) was LN(+). The average THC was significantly higher in the LN(+) group than in the LN(−) group (252.94±69.19μmol/L versus 203.86±83.13μmol/L, P=0.01). A multivariate analysis showed an independent relationship between the probability of axillary metastasis, elevated THC level (P=0.01), and tumour size (P=0.001). The odds ratio with THC≥140μmol/L was 13.651 (1.781–104.560), whereas that of tumour size with a 1cm increment was only 1.777 (1.283–2.246). ConclusionsThe THC level and the tumour size are independent and preoperative predictors of axillary nodal status; these variables may improve the diagnosis of patients with lymph node metastasis.