PURPOSE In 2006, the American Society of Clinical Oncology (ASCO) Board of Directors (BOD) approved a policy and a set of procedures for endorsing clinical practice guidelines that have been developed by other professional organizations. METHODS The Cancer Care Ontario (CCO) Guideline on Non-Hormonal Therapy for Men With Metastatic Hormone-Refractory Prostate Cancer (HRPC) was reviewed for developmental rigor by methodologists. An ad hoc prostate cancer guideline review panel consisting of prostate cancer experts reviewed the content. Results The ASCO ad hoc prostate cancer guideline review panel concurred that the recommendations are clear, thorough, based on the most relevant scientific evidence in this content area, and present options that will be acceptable to patients. The CCO guideline was subsequently endorsed by the ASCO BOD. The guideline recommends the use of docetaxel, prednisone/hydrocortisone, and/or mitoxantrone in specific settings. Docetaxel-based chemotherapy is the only treatment that has demonstrated an overall survival benefit in men with HRPC. The use of estramustine in combination with other cytotoxic agents is not recommended. Continued gonadal androgen suppression and discontinuance of antiandrogens is recommended for men receiving chemotherapy. CONCLUSION The review panel agreed with the recommendations as stated in the CCO guideline, with the following qualifications: two of the ASCO content reviewers noted the importance of considering other, nonhormonal therapies in this context that are beyond the scope of this guideline. The review panel notes that CCO has published separate guidelines on radiopharmaceuticals and bisphosphonates in men with castration-resistant (ie, hormone-refractory) metastatic prostate cancer.