WHO set target to reduce mortality attributable to hepatitis B(HBV) and hepatitis C(HCV) by 65% by 2030. While national mortality data from cirrhosis(CIR) and hepatocellular carcinoma(HCC) exist, proportion of cases due to HBV/HCV are unknown. A study protocol was developed to calculate the attributable fraction of HBV, HCV and other risk factors(RF) for CIR and HCC in a standardised wayand piloted in Sofia(Bulgaria) and Lisbon(Portugal).