The purpose of the studies was to show the relationships between secondary hyperlipaemia and post-vaccination nephritis induced by lapinized vaccine with additional infection with the living virus of pig plague and the virus itself. CT, CF, LT, FFA and LP fractions were studied in the serum of blood taken from the vena cava cranialis from piglets weighing 30 - 40 kg, of the large white breed. In the animals of group 1, in the initial series a, series b - immunized with lapinized vaccine, series c - immunized and infected with virulent viruses, and also in group 2d - infected with the virus itself, the concentration of the lipids mentioned above was studied by the methods used elsewhere. The kidneys of the animals in series c and group 2d were examined histopathologically, staining them with h.e. and oil red solution neutral to fats. Multifocal inflammation reaction with the presence of fine-grained lipids were found. Particularly in group 2d the pathomorphological image, by its intensiveness and extensiveness pointed to severe inefficiency of kidneys. In series b and c of group 1a linear increase in the concentration of the lipids studies was found, as compared with series a. Hyperlipaemia was most distinctly marked in group 2d. This leads to the conclusion that hyperlipaemia may occur in severe viral nephritis. The extention of hyperlipaemia depends on the degree of the organ damage, which was more advanced in group 2d than in series c of group 1. Vaccination with lapinized vaccine caused a moderate increase of lipids in blood serum, which oscillated on the line of significance.