Among the metal-oxide nanoparticles, pure and doped zinc oxide (ZnO) has been widely studied due to their potential applications, such as electrical, thermal and optical materials. In this context, samples of undoped ZnO and Cr-doped ZnO powders were prepared using a solution-combustion route. The formation of the combustion products was confirmed by X-ray diffraction analysis. The samples were well characterized using the Fourier transform infrared spectroscopy and scanning electron microscopy techniques. In the sample, photoluminescence studies showed that ZnO could be excited at 267 nm, while an ultraviolet emission centred at ∼383 nm was exhibited. Antibacterial-activity testing was carried out using the disc-diffusion method.