In 27 patients with lupus erythematodes diseminatus the determinations of the LE-cells according to the macromethod (Zimmer and Hargraves) and the micromethod (Mudrik and co-workers) were compared with the demonstration of antinuclear factors according to the indirect immunofluorescence and immune enzyme technique. The sensitiveness of the two last-mentioned immunomorphological methods is somewhat larger. In these cases the size of the titre of the antinuclear factor almost always correlates positively with the number of the LE-cells. For the purpose of the initial diagnostics and the judgment of the course a morphological method cannot be renounced, since in the acute episode a high consumption of the antinuclear factor the immunological methods negatively correlate with the number of the LE-cells. The immune enzyme technique is to be recommended on account of the smaller expenditure, permanence of the preparations and high sensitiveness as alternative method of the immunofluorescence technique. In the micromethod the large variation is opposite to the advantage of the slight quantity of blood and to an always existing evaluability. Investigations of the lymphocytes of patients with lupus erythematodes disseminatus by means of the lymphocyte transformation test and the determination of the B-cells with the help of the direct immune peroxidase technique refer to the close pathogenetic connections of cellular and humoral immune reactions in this disease.