In this study, ferromagnetic cobalt ferrite (CoFe₂O₄) fibers were synthesized by electrospinning technique using a DMF/ethanol mixed precursor solution of poly (vinyl pyrrolidone) (PVP) and cobalt and iron (III) nitrates. The as-spun precursor fibers were characterized using thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) analyses and calcined at 500, 600 and 800 °C with a heating rate of 2 °C/min to obtain CoFe₂O₄ fibers. Morphological studies confirmed the formation of a continuous bead-free fiber structure in the calcined samples with an average fiber diameter and particle size of 208 nm and 48 nm respectively. Magnetic hysteresis loops of CoFe₂O₄ fibers revealed their ferromagnetic nature, with a maximum saturation magnetization of 76.5 emu/g and a coercivity of 948 Oe. At room temperature, the variation of resistance and the corresponding response toward various test gases of different concentrations were systematically investigated. The sensing response of CoFe₂O₄ fibers toward ammonia was found to be better than toward other test gases such as ethanol, methanol, acetone, and 2-propanol. CoFe₂O₄ fibers showed good reproducibility and a maximum response of 0.42 at 900 ppm concentration of ammonia. They also exhibited the ability to sense a very low concentration of ammonia (even at 25 ppm) at room temperature.