We report the effects of heat treatment on ZnxNi1 − xFe2O4 (x = 0, 0.5 and 1.0) and MnFe2O4 ferrite nanoparticles. The as-prepared compounds were sintered from 400°C to 1100°C. Pure ZnFe2O4 (x = 1.0) and MnFe2O4 could be obtained under low reaction temperature of 200°C. NiFe2O4 (x = 0) and Zn0.5Ni0.5Fe2O4 (x = 0.5) nanoferrites crystallized with single phase cubic spinel structure after annealing at 600°C. The single phase cubic spinel structure of these compounds was destroyed after annealing at temperature above 700°C. The magnetization measurements indicate superparamagnetic behavior of the nanosized compounds produced.