In the present work, acetone and ethanol sensing characteristics of wet chemically prepared magnesium zinc ferrite (MZFO) nano-particles have been investigated. X-ray diffraction and electron microscopy studies are carried out to know the phase formation behaviour and microstructure evolution of the synthesized particles. The gas sensing characteristics (response %, response time, recovery time, etc.) are estimated by varying the operating temperature of the sensor and concentrations of the test vapours. It is observed that the nanocrystalline MZFO-based sensor is more sensitive to acetone than ethanol. In addition, the sensor can detect even 10 ppm of acetone and ethanol vapours. The excellent repeatability of the sensing performances is verified by switching the sensor back and forth between air and test vapours.