Increasing numbers of unidentified cadavers have recently become an important forensic problem in many countries. To identify such cadavers, DNA typing method is widely used. However, as this technique requires reference DNA samples, a method that would quickly narrow down possible candidates for the cadavers is needed to enable rapid identification. Unfortunately, no really reliable methods suitable for this purpose have been available; however, methods using the human parasites, JC virus, BK virus and EB virus, have been reported. These new methods narrow down the candidates by elucidating geographic origins. Though not detectable in all cases, results using such methods with several parasites have enabled us to estimate geographic origins of unidentified cadavers with a high detection rate.