Purpose: An American Society of Clinical Oncology (ASCO) provisional clinical opinion (PCO) offers timely clinical direction to ASCO's membership following publication or presentation of potentially practice-changing data from major studies. This PCO addresses the integration of palliative care services into standard oncology practice at the time a person is diagnosed with metastatic or advanced cancer. Clinical Context: Palliative care is frequently misconstrued as synonymous with end-of-life care. Palliative care is focused on the relief of suffering, in all of its dimensions, throughout the course of a patient's illness. Although the use of hospice and other palliative care services at the end of life has increased, many patients are enrolled in hospice less than 3 weeks before their death, which limits the benefit they may gain from these services. By potentially improving quality of life (QOL), cost of care, and even survival in patients with metastatic cancer, palliative care has increasing relevance for the care of patients with cancer. Until recently, data from randomized controlled trials (RCTs) demonstrating the benefits of palliative care in patients with metastatic cancer who are also receiving standard oncology care have not been available. Recent Data: Seven published RCTs form the basis of this PCO.