OBJECTIVES: To calculate the direct medical costs associated with HCV health states by eliciting expert opinion. METHODS: Portuguese-specific annual direct medical costs of HCV health states were estimated based on a national expert panel with 8 clinicians experienced in HCV treatment at the national level. We adopted a two-stage modified Delphi technique: First, experts independently answered questions concerning the resource use associated with each HCV-related health state. Secondly, a consensus meeting was held where experts were encouraged to revise their earlier answers after the panel discussion. The annual cost for each health state of HCV disease was thereafter obtained by multiplying unit costs with the consensus scores for each resource use. Unitary costs were obtained through national official sources. Fibrosis (F0-F3), compensated cirrhosis (CC), decompensated cirrhosis (DC), hepatocellular carcinoma (HCC) and liver transplantation were set as the different HCV health states with relevance for clinical and economic research. RESULTS: Estimated annual costs per HCV health state were the following: fibrosis (F0-F3) was €580, in advanced liver disease, CC was €1,156, whereas DC was €8,222 for the first year and €9,085 for subsequent years. For HCC first year, the annual cost was €20,749, whilst €19,088 for subsequent years. For liver transplant, first year cost was €112,072, while for subsequent years it was €7,558. The considerable difference between the costs associated with the first and subsequent years is due to the transplant procedure being the cost driver for this health state. CONCLUSIONS: Overall Cost of illness associated with HCV infection is substantial in Portugal and increases throughout the liver disease health states. Strategies aiming to treat HCV infection have the potential to decrease the disease progression and subsequent total costs associated with HCV-related liver disease. The results from our research highlight this point and may support cost-effectiveness analysis in the evaluation of those strategies.