Background: We conducted a multicenter, randomized trial of early integrated palliative and oncology care in patients with advanced cancer to confirm the benefits of early palliative care (PC) seen in prior single-center studies. Methods: We randomly assigned patients with newly diagnosed incurable cancer to early integrated palliative and oncology care (n = 195) or usual oncology care (n = 196) at sites through the Alliance for Clinical Trials in Oncology. Patients assigned to the intervention were expected to meet with a PC clinician at least monthly until death, whereas usual care patients consulted PC on request. The primary endpoint was the change in quality of life from baseline to week 12 per the Functional Assessment of Cancer Therapy-General (FACT-G). Secondary outcomes included anxiety, depression, and communication about prognosis and end-of-life care. Results: Due to significant morbidity and a high proportion of measures that were not completed within the protocol window or for unknown reasons, the rate of missing data was high. We anticipated that 70% of patients (n = 280) would complete the FACT-G at baseline and week 12, but only 49.3% (n = 193/391) completed the measure. Delivery of the intervention was also suboptimal, as 14.9% (n = 29/195) of intervention patients had no PC visits by week 12. Intervention patients reported a mean 3.35 (standard deviation [SD] = 14.7) increase in FACT-G scores from baseline to week 12 compared with usual care patients who reported a 0.12 (SD = 12.7) increase from baseline (p = 0.10). Conclusion: This study highlights the difficulties of conducting multicenter trials of supportive care interventions in patients with advanced cancer. Clinical Trials Registration: NCT02349412.