Present paper reports the modification in band gap and structure of CdS(∼2.4 eV) and formation of a new ternary semiconducting material. The band gap tailoring is done by preparing a mixed lattice with different concentration of a low‐band‐gap material, NiS (∼0.8 eV), which leads to the formation of new set of materials. New ternary, having tunable band gap has potential application in photovoltaic devices. The optical‐absorption studies showed shift in band edge towards higher wavelength. The band gap calculation was done using Tauc relation, which showed that with variation of x in Cd(1‐x)NixS, band gap could be tailored as low as ∼1.7 eV for x = 0.05. Larger concentration of Ni may yield further shift in band gap.