In this study, we developed a novel method to concentrate Norovirus (NoV) in environmental swabs by ethanol precipitation with glycogen to investigate the route of transmission in outbreaks of NoV infection. The recovery rates of the samples were significantly higher than with previous methods, the mean recovery rates were almost 100%, and the lowest detectable copy number was 1.5×10² in 15 ml of sample. The precipitate was obtained by low-speed centrifugation and could be used as a sample for the following steps: RNA extraction and virus detection using RT-PCR, without removing glycogen. The novel method was able to concentrate NoV regardless of the genotype and amount of virus in the samples, and all procedures could be finished within about one hour. The data suggest that the novel method is useful for the detection of NoV from environmental materials.