Nowadays, the development of approaches to increase the sensitivity and reduce the operating temperature of gas sensors based on metal oxides is the important task. In this paper, these problems are solved by forming zinc stannate nanostructures during hydrothermal treatment of zinc oxide nanowires. The microstructure and chemical composition of the synthesized nanostructures were studied by SEM, EDS and XPS. Sensor responses to isopropyl alcohol vapors (1000 ppm) at 120 °C, 180 °C and 250 °C were measured. It was found that the sensor response values of zinc stannate nanostructures significantly exceed the responses of zinc oxide. Moreover, zinc stannate demonstrates the response of 6.3 at 120 °C. Thus, the developed structures can be used to create sensors of reducing gases with low operating temperatures.