The present study prospectively assessed consistency of ratings of health-related quality of life between patients with hepatocellular carcinoma and two types of proxy raters, family caregivers and oncologist care providers. Patients and proxies completed the Functional Assessment of Cancer Therapy-Hepatobiliary (FACT-Hep) at baseline prior to treatment (82 patients plus proxies), at 3-months (32 patients plus proxies), and 6-months follow up (16 patients plus proxies) after diagnosis. Patient and proxy demographic data and patient medical data were also collected. At baseline, significant intra-class correlations (ICC) were found for patient--caregiver ratings of physical, social/family, and functional well-being, additional concerns (symptoms, side effects), and overall health related quality of life (HRQL); for patient--care provider ratings of physical well-being; and for caregiver--care provider ratings of physical and emotional well-being. At 3-months follow-up, the most significant number of ICCs were recorded across all three rater pairs. Significant consistencies were found for overall HRQL, and all subscale scores except for social and family well-being. The fewest significant ICCs were found at the 6-month follow-up, and were for patient--caregiver ratings of physical and functional well-being, and additional concerns; and for caregiver--care provider ratings on overall HRQL. These results suggest that family caregivers are adequate proxies of patient physical and functional well-being and additional concerns throughout the patient's illness, more so than oncologist care providers. Further research is warranted with larger samples.