Various electron microscopic (EM) and immunoelectron microscopic (IEM) techniques were used to demonstrate and identify the Newcastle disease virus (NDV) infection. By IEM, the number of virions in native allantoic fluids was increased 50-100 times in comparison with direct EM. The immunogold staining showed that a number of immunogold particles were specifically bound to the antigen determinants located on the virion surface and these results were much easier to interpret. The obtained results showed that the EM and IEM can be successfully employed for a precise and rapid detection of NDV as well as for identification of this infection among other viral or bacterial infections.