In November 2009, the American Society of Clinical Oncology (ASCO) and the Oncology Nursing Society (ONS) jointly published a set of 31 voluntary chemotherapy safety standards for adult patients with cancer, as the end result of a highly structured, multistakeholder process. The standards were explicitly created to address patient safety in the administration of parenteral and oral chemotherapeutic agents in outpatient oncology settings. In January 2011, a workgroup consisting of ASCO and ONS members was convened to review feedback received since publication of the standards, to address interim changes in practice, and to modify the standards as needed. The most significant change to the standards is to extend their scope to the inpatient setting. This change reflects the conviction that the same standards for chemotherapy administration safety should apply in all settings. The proposed set of standards has been approved by the Board of Directors for both ASCO and ONS and has been posted for public comment. Comments were used as the basis for final editing of the revised standards. The workgroup recognizes that the safety of oral chemotherapy usage, nononcology medication reconciliation, and home chemotherapy administration are not adequately addressed in the original or revised standards. A separate process, cosponsored by ASCO and ONS, will address the development of safety standards for these areas.