Background A number of clinical practice guidelines (cpgs) concerning breast cancer (bca) screening and management are available. Here, we review the strengths and weaknesses of cpgs from various professional organizations and consensus groups with respect to their methodologic quality, recommendations, and implementability.Methods Guidelines from four groups were reviewed with respect to two clinical scenarios: adjuvant ovarian function suppression (ofs) in premenopausal women with early-stage estrogen receptor–positive bca, and use of sentinel lymph node biopsy (slnb) after neoadjuvant chemotherapy (nac) for locally advanced bca. Guidelines from the American Society of Clinical Oncology (asco); Cancer Care Ontario’s Program in Evidence Based Care (cco’s pebc); the U.S. National Comprehensive Cancer Network (nccn); and the St. Gallen International Breast Cancer Consensus Conference were reviewed by two independent assessors. Guideline methodology and applicability were evaluated using the agree ii tool.Results The quality of the cpgs was greatest for the guidelines developed by asco and cco’s pebc. The nccn and St. Gallen guidelines were found to have lower scores for methodologic rigour. All guidelines scored poorly for applicability. The recommendations for ofs were similar in three guidelines. Recommendations by the various organizations for the use of slnb after nac were contradictory.Conclusions Our review demonstrated that cpgs can be heterogeneous in methodologic quality. Low-quality cpg implementation strategies contribute to low uptake of, and adherence to, bca cpgs. Further research examining the barriers to recommendations—such as intrinsic guideline characteristics and the needs of end users—is required. The use of bca cpgs can improve the knowledge-to-practice gap and patient outcomes.