Abstract <p>Despite the development of metal oxide gas sensors in recent decades, the low selectivity and high operating temperatures required for their operation have continued to drive the search for new materials for gas sensors. Significant improvements in the design of highly efficient gas sensors have been achieved due to advances in microfabrication and nanofabrication technologies and the application of nanostructured materials; therefore, the review considers the main types of conductometric sensors for gas detection with an emphasis on the use of nanomaterials in this area. Achievements in fundamental and applied research that have led to the development of highly efficient chemiresistive devices are presented. Approaches to the synthesis of new materials with unique structures and gas-sensing properties are also presented, and the prospects for new technologies and future applications of chemiresistive gas sensors are highlighted.</p>