The aim of the study was to determine the clinical significance of studying a number of autoantibodies in blood serum to detect preeclampsia as well as to carry out differential preeclampsia and arterial hypertension diagnosis. Among 76 examined women there were 28 patients with detected preeclampsia, 26 with arterial hypertension and 22 healthy pregnant women. In all patients there was determined the content of IgG autoantibodies against doublestranded DNA, two platelet membrane antigens (TrM-001-15, TrM-015-12), two kidney antigens (KiM-05-300, KiS-07-120) and antigen liver mitochondria (HMMR) by enzyme-multiplied immunoassay. The algorithm to interpret enzyme-multiplied immunoassay results for preeclampsia diagnosis was put forward. There was proved the high diagnostic value of the method.