Background: Although the use of antiviral medications (antivirals) may reduce virus-related morbidity,these drugs are often prescribed excessively.Moreover,doctors often do not have enough information about their long-term effects to prescribe them appropriately.Objective: To assess the use of antivirals among hospitals in Shanghai,China,between 2009 and 2011.Methods: A retrospective analysis was performed on the main types and manufacturers,dosages,defined daily dosages (DDDs),sales volumes,and proportions of total sales of antivirals among 105 sample hospitals in Shanghai,China,from 2009 to 2011.Results: During 2009 to 2011,antivirals experienced rapid sales growth rates compared to the sales growth rates of all drugs combined (2009: 34.92% vs.21.31%; 2010: 12.35% vs.10.63%; 2011: 22.51% vs.9.47%).Although the proportion of all drugs that were antivirals was small,the proportion increased each year,from 1% of the purchases in 2009 to 1.10% in 2010 and 1.23% in 2011.The sales of anti-hepatitis B virus nucleoside drugs,such as lamivudine,entecavir,adefovir dipivoxil,and telbivudine,showed a rapid upward trend.These drugs occupied the top rankings in terms of sales volume and dosage among the 105 sample hospitals.The antiherpes drugs valaciclovir and ganciclovir also showed an upward trend,whereas stavudine,acyclovir,and penciclovir showed a downward trend.Conclusion: The use of antiviral medications,especially those for HBV,in Shanghai,China,has shown consistently strong growth in terms of sales and dosage.There appears to be a need for antiviral medications that are safe,effective,and specific.