Background: Health-related quality-of-life (HRQOL) assessment with EORTC QLQ-C30 was prognostic for overall survival (OS) in patients with advance-stage hepatocellular carcinoma (HCC), but no data existed for early-stage patients. The HCC-specific QLQ-HCC18 has not been evaluated for prognostic value in HCC patients. Utilization of raw HRQOL data in clinical setting has been impractical and non-meaningful. Therefore we developed index scores of QLQ-C30 and QLQ-HCC18 in an attempt to enable clinical utilization of these HRQOL measurements. This study investigates the prognostic significance of QLQ-C30, QLQ-HCC18 and C30/HCC18 index-scores in patients with newly diagnosed HCC which encompasses all stages. Methods: From 2007-2011, 517 patients were prospectively recruited. HRQOL was assessed at diagnosis using QLQ-C30 and QLQ-HCC18; C30 and HCC18 index-scores were calculated from raw HRQOL data. Cox regression was performed using continuous, dichotomized QLQ-C30 and QLQ-HCC18 variables, or index-scores, together with clinical factors to identify independent factors for OS. Various multivariate models were validated with c-index and bootstrapping for 1000 replications. Results: Four hundred and seventy two patients had complete HRQOL data. Their median OS was 8.6 months. In multivariate analysis, independent prognostic HRQOL variables for OS were QLQ-C30 pain (HR 1.346 [1.092-1.661], p = 0.0055), QLQ-C30 physical functioning (HR 0.652 [0.495-0.860], p = 0.0024); QLQ-HCC18 pain (HR 1.382 [1.089-1. 754], p = 0.0077) and QLQ-HCC18 fatigue (HR 1.441 [1.132-1.833], p = 0.0030). C30 index-score (HR 2.143 [1.616-2. 841], p < 0.0001) and HCC18 index-score (HR 1.957 [1.411-2.715], p < 0.0001) were highly significant factors for OS. The median OS of patients with C30 index-score of 0-20, 21-40, 41-60, 61-100 were 16.4, 7.3, 3.1, 1.8 months respectively (p < 0.0001); while for HCC18 index-score: 16.4, 6.0, 2.8, 1.8 months respectively (p < 0.0001). All the multivariate models were validated, with mean optimism < 0.01. The bootstrap validated c-index was 0.78. Conclusions: QLQ-C30 and QLQ-HCC18 were prognostic for OS in patients with newly diagnosed HCC irrespective of stage. Both C30 and HCC18 index-scores were highly significant prognostic factors for OS in newly diagnosed HCC patients. Index-scoring provides an effective way to summarize, analyze and interpret raw HRQOL data, and renders QLQ-C30 and QLQ-HCC18 meaningful and communicable in clinical practice. Index-scores could potentially serve as a standardized tool for future HRQOL research.