Maize yellow stripe virus (MYSV) is a new virus isolated on maize in Egypt Based on symptoms, host range, virus vector relationships, nucleoprotein (NP), non-capsid protein (NCP) and particle shape (filaments of 4-5 nm wide), MYSV was provisionally classified in the tenuivirus group. However, unlike the members of the tenuivirus group which are all transmitted by planthoppers, MYSV is transmitted by a leathopper, Cicadulina chinai. Moreover, no clear serological relationwas detected between MYSV and tenuiviruses. The genome of MYSV was analysed in order to understand this discrepancy and to obtain the molecular data required for the classification of this new virus. Based on RNA extracts from the purified virus or directly from infected plants, it appeared that MYS V has a multipartite genome. Some parts of the genome could be amplified with primers specific to the 5' and 3' common ends of tenuivirus RNAs. Three virus-specific contigs were obtained by cloning and sequencing various amplification products. However, no similarities were found between these MYSV-specific sequences and any of the sequences available in the GenBank. This, together with the transmission data, indicates that MYSV is distinct from the tenuivirus group. However, further results are required to definitely classify this virus.