With the aim of studying molecular mechanisms of virulence and immunogenesis of Egtved virus, monoclonal antibodies (MAbs) were produced against 4 dominant virus proteins (G, N, M, and M2). The reactivity of each MAb was determined by ELISA, immunoblotting, immunofluorescence and plaque neutralization. Antibodies specific for each of the 4 proteins, as demonstrated by immunoblotting, gave characteristic reactions in ELISA as well as immunofluorescence. None of the MAbs were able to neutralize virus in vitro. When analysed in immunofluorescence using cell cultures fixed at different times after inoculation with live virus, the N-protein was first to be detected followed by M,, G and M2. G-specific MAbs reacted with either a 'reticular', or a 'Go1gi'-form of the G-protein. Results are consistent with published information on the protein compositon and cellular appearance pattern of other rhabdovimses studied in vitro.