Hantaviral sequences were recovered from the lung tissue of an Asian house rat (Rattus tanezumi) captured in Serang, Indonesia. Phylogenetic analysis of partial L, M and S segment sequences showed that they belonged to a novel hantavirus provisionally named Serang virus (SERV). Notably, SERV is distinct from the hantaviruses associated with rodents of the species Rattus: Seoul virus associated with Rattus norvegicus worldwide and Gou virus isolated from Rattus rattus in China. Instead SERV appeared more closely related to Thailand virus (THAIV) carried by the great bandicoot rat (Bandicota indica). These results suggest the possibility that SERV originated via host-switching, with a possible scenario of (pre)-THAIV 'jumping' from (pre)bandicoots to rats and colonizing this new host species.