CdS and Cr0.04Cd0.96-xNxS (x = 0, 2, 4, 6, and 8 at %) nanoparticles were synthesized through simple chemical co-precipitation method. The synthesized nanoparticles were analyzed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDAX), UV–vis diffuse reflectance spectroscopy (DRS), and vibrating sample magnetometer (VSM). XRD studies confirmed the cubic structure of nanoparticles with a crystallite size of around 1–2 nm. Incorporation of Cr and N elements into the host CdS matrix is confirmed through EDAX analysis. UV–vis DRS spectra of the nanoparticles revealed an enhancement in energy band gap values, and a room temperature ferromagnetism is observed in Cr0.04Cd0.96-xNxS (x = 0, 2, 4, 6, and 8 at %) nanoparticles which is favorable for spintronic applications.