Background: Understanding challenges of family caregivers within specific palliative care contexts is needed. Objective: To describe the challenges of family caregivers of patients with cancer who receive outpatient palliative care. Methods: We summarized the most common and most challenging problems for 80 family caregivers of cancer patients receiving outpatient palliative care in the midwestern United States. Results: Caregiver worry and difficulty managing side effects or symptoms other than pain, constipation, and shortness of breath were most common. "Financial concerns" was cited most as a "top 3" problem. Almost half of caregivers reported "other" problems, including family members, patient physical function, care coordination, and patient emotional state. Conclusions: The most common and most challenging problems of family caregivers of cancer patients receiving outpatient palliative care may differ from those experienced in other serious illness care contexts. Comparative studies on caregiver problems across the cancer care continuum can help develop and refine interventions.