Background:  Sentinel node biopsy (SNB) has been a major change in surgical technique for the management of early breast cancer. In June 2008, the National Breast and Ovarian Cancer Centre (NBOCC) released evidence‐based guidelines for the use of SNB in Australia. During 2010, NBOCC undertook a cohort study to identify the extent to which clinical practice in Australia reflected the recommendations for use of SNB in the 6 months after release of the guidelines. Methods:  Records obtained from four datasets, Royal Australasian College of Surgeons National Breast Cancer Audit, New South Wales Central Cancer Registry, Victorian Cancer Registry and Medicare Benefits Schedule records, were analysed to determine the extent to which the four key guideline recommendations had been implemented. This was supplemented by an audit of written SNB protocols of a sample of pathology laboratories in Australia. Results:  Across all cohorts, between 78 and 83% of women in Australia with tumours ≤3 cm had an SNB. Data were not available to indicate whether nodes were clinically negative. The likelihood of women having an SNB decreased outside the metropolitan regions, for women treated as public patients compared with private patients and as the size of the tumour increased. In 90% of procedures both preoperative lymphoscintigraphy with isotope and blue dye were used. Conclusion:  The findings from the study confirm that best practice recommendations from the NBOCC guidelines for SNB were largely being implemented for women with early breast cancer in Australia within 6 months of their release.