The layout of Morozov Children's Hospital was based on a pavilion principle, which was chosen after studying European experiences of similar institutions. Separate isolated buildings were constructed for different categories of patients depending on the type of disease to prevent cross-infection. This decision was made by a special medical commission, which included the chief physician of St. Vladimir Hospital S. Vasilevsky, the chief physician of Sokolnicheskaya Hospital V. Shnaubert, and the chief physician of the planned Morozov Hospital N. Alekseev. Architect I. A. Ivanov-Shitz worked on the site plan and the arrangement of the buildings according to this program.

The hospital building was based on a spacious common hall, adjacent to smaller wards.

The building for the diphtheria department was constructed in 1902 and opened in January 1903 as one of the first departments of Morozov Hospital. It was designed for 40 patients and included 2 pavilions with 14 beds each, 2 steam rooms with 2 beds each, 2 wards with 3 beds each, 1 ward with 2 beds, an operating room, a laboratory, 2 buffets, 2 closets, and 2 rooms for children's daytime stay. The layout and finishing of the building were similar to the 'scarlet fever building' of the hospital. If necessary, the building could be divided into two separate departments with independent entrances to prevent the spread of infection.

Initially, the building was single-story, with a second floor only on the left side, where the main and auxiliary entrances were located. The asymmetric composition gave the building dynamism. The center of the right, single-story part was highlighted by a risalit with a large window, wider than the others. All windows were adorned with modern 'sandrik' decorations, standing out against the background of unplastered brick walls. The building stood on a low plinth with recessed windows.

In 1950, the single-story part of the building was raised with a second floor. During the Soviet era, extensions were added to the building, altering the original composition of the structure. Nevertheless, the main core of the building has been well preserved.