['Fulminant hepatitis B is a clinical syndrome that results from massive necrosis of liver cells leading to the development of hepatic encephalopathy. The aim of this study was to evaluate the efficacy of lamivudine in patients with fulminant hepatitis B and study the prognostic factors.', 'A matched retrospective cohort study using data on fulminant hepatitis B patients derived from our hospital database was conducted. Forty patients receiving lamivudine treatment were selected into the lamivudine treatment group with another 40 without lamivudine treatment studied as control. They were matched for sex, age and HBeAg status with lamivudine treatment group. The mortality of patients in two groups was compared. The influential factors on the mortality were studied by Cox proportional hazards model.', 'The mortality of patients in the lamivudine group (n=38) was significantly lower than that of the control group (n=39) (63.2 vs. 84.6%; χ(2) =4.609, P=0.032). For patients without systemic inflammatory response syndrome (SIRS), the mortality of patients in the lamivudine group (n=25) was significantly lower than that of the control group (n=26) (52.0 vs. 80.8%; χ(2) =4.747, P=0.029). In multivariate Cox proportional hazards analyses, for patients without SIRS, age (P=0.037), ratio of total to direct bilirubin (P=0.008), treatment method (P=0.005) and the decline of hepatitis B virus (HBV) DNA load during therapy (P=0.019) were independent predictors of prognosis.'] Is lamivudine treatment associated with improved survival in fulminant hepatitis B?