Facile synthesis of SnO2-MWCNT nanocomposites using sol-gel route. Response of sensor increase from 50% to 80% due to loading of MWCNT. SnO2-MWCNT nanocomposites based sensor delineates ultrafast response and recovery. Sensors are very selective toward acetone and insensitive to saturated moisture. Sensors remain stable for more than one year.