The aim of the study is to see if Bone Scan (BS) - when performed the day before the operation-interferes with the results of the Sentinel Lymph Node (SLN) technique using radiocolloids (their pre-operative imaging and their peroperative research). Therefore, the data of 393 patients who had one selective lymphadenectomy of the SLN(s) followed by the complete axillary node (AxN) clearance for Breast Cancer and among whom 309 patients had one BS the day before the operation (and just before the injection-s for the SLN) and 84 did not, were analysed and compared. The two series presented the same characteristics with regard to: age, clinical staging of the tumour, kind of injection-s performed (intradermic and paratumoural and/or intraparenchymal and peritumoral), pathological size of the tumour, percentage of cases with no AxN invasion, total number of AxN removed by the surgeons. The percentages of no axillary SLN visualisation, the mean numbers of axillary SLN visualised on pre-operative lymphoscintigram as well as of SLN removed by the surgeons were not statistically different in the groups of patients with (respectively, 12.11, 2.6 and 3.03) and without BS (respectively, 12.99, 2.7 and 2.96). More noteworthy, the false negative (FN) rate of the SLN technique, albeit having a higher observed value in the group with BS (9.6%, 12/125), did not differ significantly from that in the group without BS (5.6%, 2/36). The accuracies (overall correct classification rates), the sensitivities and the negative predictive values of the SLN technique also did not differ significantly between the two groups. It is concluded that the SLN technique can be accurately performed just after one BS.