Co1−xCuxFe2O4 (x = 0.0, 0.10, 0.20 and 0.30) nanoparticles with interesting morphologies and magnetic properties were synthesized via thermal decomposition of Cu2+-substituted Co–Fe glycolates. The Cu2+-substituted Co–Fe glycolates were prepared first via a glycolate route which were then calcined at 500 °C to obtain Cu2+-substituted cobalt ferrite nanoparticles. The Cu2+-substituted Co–Fe glycolates and the Cu2+-substituted CoFe2O4 nanoparticles were characterized by various characterization techniques such as XRD, TGA, FT-IR, CHNS, FE-SEM, EDX, TEM, DRS and BET. The morphology of Cu2+-substituted cobalt ferrite nanoparticles could be tailored (hexagonal particles, hexagonal plates and near micro-spherical particles) by varying the concentration of Cu2+ used during the synthesis. Magnetic parameters such as saturation magnetization, coercivity and remanence of the Co1−xCuxFe2O4 nanoparticles were studied at 300 K and 15 K and the observed results have been explained on the basis of concentration of Cu2+, cationic distribution, size and morphology of the nanoparticles.