Magnesium ferrite (MgFe2O4) nanostructures were successfully fabricated by electrospinning method. X-ray diffraction, FT-IR, scanning electron microscopy, and transmission electron microscopy revealed that calcination of the as-spun MgFe2O4/poly(vinyl pyrrolidone) (PVP) composite nanofibers at 500-800 A degrees C in air for 2 h resulted in well-developed spinel MgFe2O4 nanostuctures. The crystal structure and morphology of the nanofibers were influenced by the calcination temperature. Crystallite size of the nanoparticles contained in nanofibers increased from 15 +/- A 4 to 24 +/- A 3 nm when calcination temperature was increased from 500 to 800 A degrees C. Room temperature magnetization results showed a ferromagnetic behavior of the calcined MgFe2O4/PVP composite nanofibers, having their specific saturation magnetization (M (s)) values of 17.0, 20.7, 25.7, and 31.1 emu/g at 10 Oe for the samples calcined at 500, 600, 700, and 800 A degrees C, respectively. It is found that the increase in the tendency of M (s) is consistent with the enhancement of crystallinity, and the values of M (s) for the MgFe2O4 samples were observed to increase with increasing crystallite size.