In this work, the effects of Co2+ ions on the structural and luminescent properties of intrinsic and Mn doped CsPbCl3 NCs were studied by using photoluminescence (PL) spectroscopy, X-ray diffraction (XRD) spectroscopy, and transmission electron microscopy (TEM). The undoped and Mn doped CsPbCl3 NCs with various Co/Pb molar ratios were synthesized at 190 °C. It was found that the quantum yields of purple emissions in these CsPbCl3 NCs were greatly enhanced up to 30% after Co2+ ions were doped. The diffraction peaks in XRD patterns shifted to a large angle with the increase of Co/Pb molar ratio, indicating Co doping in Pb-site. Further both intrinsic and Mn doped CsPbCl3 NCs exhibited uniform cubes with average sizes of 8–10 nm and good crystallinity after Co doping. The enhancement of purple emissions from excitons in the CsPbCl3 NCs was related to the reduction of nonradiative defects in these NCs through Co2+ doping.