Seasonal influenza causes significant morbidity worldwide and has a substantial economic impact on the healthcare system. To assess the cost-benefit relation of implementing a real-time influenza test in emergency rooms (ER) of German hospitals. A deterministic decision-analytic model was developed simulating the incremental costs of using the Solana® Influenza A+B test, compared to those of using conventional clinical judgement alone to confirm or exclude influenza in adult ILI (influenza-like illness) patients, in German ER, prior to hospitalization. Direct costs were evaluated from the hospital perspective, considering resource use directly related to influenza testing and treatment, as well as indirect costs incurred by nosocomial influenza transmission. Through base-case analysis and assuming an influenza prevalence of 42.6%, real-time testing with Solana® reduced average costs of hospitalized ILI patients by €132.61, per tested patient. Moreover, the Solana® saved €6.9 per tested patient in favor of the hospital. In probabilistic sensitivity analysis, under all reasonable assumptions, implementing the Solana® saved on average €144.13 as compared to applying the clinical-judgement-only strategy, thus, it was found to be constantly less expensive. Using highly sensitive and specific real-time influenza tests in ILI patients at German ER might significantly reduce hospital expenditures.