The Core Department of Morozov Children's Hospital is located in the central part of the hospital complex, behind the Outpatient Building and the Department for Suspicious Patients. Next to it was the Infectious Diseases Department.

The building of the Core Department was constructed in 1903-1904 according to the design of architect I.A. Ivanov-Shitz in the Art Nouveau style. Like other hospital buildings, it is made of red brick with white stone details on the facades.

The small asymmetrical building has a two-story left part, where the second floor was intended for staff. The right part of the facade, highlighted by a large window, features a risalit with beveled corners. The composition of the building is similar to other hospital buildings, including two Infectious Disease Departments and the Diphtheria Building. The facade almost completely mirrors the facade of one of the Infectious Disease Departments, but in a mirrored reflection.

On the left side of the Core Department facade, there are two entrances: a main one with a small vestibule and a secondary one. The center of the facade is adorned with large windows, providing good lighting for the interior spaces. On the opposite side of the building, the risalit with three narrow vertical windows is interesting. The building stands on a low plinth and has two tall chimneys.

The Core Department, designed for 22 beds, opened in 1905. Like in other hospital buildings, the floors in the rooms were covered with oak parquet, and the walls were painted with oil and glue paints. The height of the rooms ranged from 3.5 to 4.5 meters. The building was equipped with central steam-water heating and electric lighting.

The building was not altered during the Soviet era and has preserved its volumetric-spatial composition and facade decor. The white stone window frames contrast with the red brick walls. A white stone plaque above the entrance on the left side of the facade has been preserved. The large window in the risalit of the right part of the facade became part of the entrance opening during the Soviet era, but this did not change the overall perception of the architectural monument from the early 20th century.