One year after the first outbreak infections with SARS associated coronavirus were again reported and the clinical picture varied. Because health care facilities will have to initiate immediate preventive action in cases of probable SARS we tested the potential of PCR to exclude SARS associated coronavirus in patients hospitalized with respiratory symptoms. Based on primers published recently a real time Taqman PCR was established and evaluated. Lower respiratory tract specimens of patients with acute exacerbation of COPD were investigated. 141 patients with mild to moderate COPD were included. The assay was specific, sensitive, precise and reproducible and allowed absolute quantification without cross-reactivity to other respiratory viruses. None of the samples were positive for SARS associated coronavirus. Our RT-PCR for SARS associated coronavirus is a valid and practicable method to further exclude SARS in X-ray negative patients with respiratory symptoms, even in the presence of other respiratory RNA viruses.