Aim: To evaluate the cost-effectiveness of influenza vaccination at the workplace in Germany. Introduction: Every year 5—30 % of the population suffer from influenza like illnesses. Between 1 % and 26 % of 18—64 year olds may suffer from influenza annually. There is a significant rise in absenteeism in the working population during outbreaks of influenza and this proves costly to employers. Work loss due to influenza ranges from 0.79 to 4.9 days off work per influenza episode. Those who stay at work work at half their usual productivity. Methods: An employer perspective, decision analysis model was developed to assess the costs, benefits and cost-effectiveness of a workplace influenza vaccination programme. Input parameters were taken from national data sources and published literature. The model estimates the financial benefits resulting from reduced absence from work and reduced productivity loss whilst at work. Results are presented as a net saving and a rate of return (cost benefit ratio) to the employer. Results: The baseline results estimated the rate of return at 2.71; the cost per day off work avoided by implementing the vaccination programme at € 71.—; and the cost per production day gained at € 55.—. The key cost drivers were the wage level and administration costs of providing the vaccine, and also the incidence of influenza attacks, the proportion of people taking time off with influenza and the days off work per influenza episode. Conclusion: An influenza vaccination programme for employees can produce significant cost-savings for firms in Germany, particularly where the wage rate is high compared with the cost of vaccine administration.