Implementation of sentinel lymph node biopsy (SLNB) outside a specialized center requires adequate quality control and quality assurance for optimal patient care. We examine the model of a supervising breast cancer unit in improving quality assurance in the treatment of breast cancer patients. A total of 76 SLNBs followed by level I/II axillary dissection were performed in the general hospital by using patent blue V alone. Patient selection, technical information, documentation, pathologic examination of the sentinel lymph node (SLN), and surgical training were provided by the supervising breast cancer unit. In 73 of 76 SLNBs, identification of the sentinel node was successful. The false-negative rate was 2.7% and the accuracy was 98.6%. The results of the procedure in the general hospital were comparable with the results of the supervising breast cancer unit. The model of a supervising breast cancer unit seems to accelerate surgeons' learning curve and may provide support for appropriate application of the SLNB in a wider number of nonspecialized centers.