Nickel doped cadmium sulfide (CdS:Ni2+) nanocrystals were synthesized at three different pH values. Nanocrystalline state of nickel doped cadmium sulfide material was established using X-ray diffraction analysis. Peak broadening and peak shifts in the XRD spectra were caused by the replacement of Cd2+ with Ni2+. Particles size (similar to 62 nm) and the morphology of the synthesized nanoparticles were established through SEM analysis. The TEM analysis further established the presence of nanostate with particles size of 35 nm. The EDS analysis confirmed the existence of Ni in all the three samples. Blue shift in the absorption region and increase in the bandgap to the larger value (3.72 eV) were attributed to the nano dimensional state and incorporation of dopant into the host lattice. Weak metal sulfur interaction was identified from the FT-IR spectroscopy. The room temperature magnetic studies showed that 10% nickel doped CdS at 10 pH, 11.0 pH and 9.0 pH showed weak ferromagnetic and strong ferromagnetic hysteresis. The variations in the magnetic property of the nanomaterials were caused by the weak interaction of Ni2+ with the host material. (C) 2012 Elsevier Ltd. All rights reserved.