Nowadays an important task is the development of nanostructures of Zn–Sn–O ternary oxide system, which are of practical interest for various fields, including gas sensors and photocatalysts, lithium-ion batteries, and solar cells. Zinc stannate nanowires were formed by hydrothermal treatment of preliminary synthesized zinc oxide nanowires in a solution of potassium stannate and carbamide. Using scanning electron microscopy and backscattered electron diffraction, the samples were found to have a Zn2SnO4 structure, and their geometric dimensions did not change compared to the initial zinc oxide nanowires. The diameter of the obtained structures is about 300 nm, and the length is about 2 μm. According to X-ray photoelectron spectroscopy data, as a result of hydrothermal treatment, the surface structure changes, tin atoms are incorporated into the crystal structure of zinc oxide. A study of the gas-sensitive properties of the Zn2SnO4 layers have shown that they are more efficient in detecting isopropyl alcohol vapors compared to the initial zinc oxide nanowires. Zn2SnO4 layers allow detecting isopropyl alcohol vapors at temperatures of about 150°C. The sensor signal with respect to 1000 ppm C3H7OH is 3.79.