Objective. To detect cytotoxic effects of blood serum (BS) from schizophrenia patients on astrocytes and neurons in the human fetal brain organotypic culture. Material and methods. Authors studied the human fetal brain organotypic culture after the application of BS from 20 healthy donors and 33 untreated patients with attack-like progressive schizophrenia (ICD-10: schizophrenia, paranoid type, F20.02; F20.22). The numerical density of degenerating cells was estimated by the optical dissector method in Nissl stained sections. A qualitative electron microscopic study of glial cells, neurons and neuropil as well as morphometric study of the ultrastructure of astrocytes were performed. Results. Authors found no significant effect of BS from patients with schizophrenia on the numerical density of degenerating cells as compared to BS from healthy donors. The qualitative study detected ultrastructural alterations in astrocytes and microglial cells but not in neurons. The morphometric study of astrocytes demonstrated a decrease of the area of astrocytes, their nuclei (р<0.001) and cytoplasm (р<0.05), reduced number of mitochondria (р<0.05) and increase in the number and volume fraction of lypofuscin inclusions (р<0.01). Conclusion. The application of BS from untreated schizophrenia patients does not influence the cell survival in human fetal brain organotypic culture and the ultrastructure of neurons and neuropil but induces the hypotrophy of astrocytes and increase in the number of lypofuscin inclusions. The data suggest that astrocytes are specific target for the damage effect of BS from schizophrenia patients.