NiFe2O4 nanoparticles were synthesized via solid-state reaction. The effects of the reaction parameters, namely dispersant content, calcination temperature and annealing time on particle size and morphology were investigated. Magnetic properties of NiFe2O4 nanoparticles were tested. The formation mechanism of nanoparticles by solid-state reaction was also discussed. The results indicated that the synthesized nickel ferrite particles were of nanometer size with different morphologies by slight variation of the reaction conditions. The solid-state reaction technique is a simple, convenient, inexpensive and effective preparation method of NiFe2O4 in high yield.