Wool protection against moths is an important concept in wool finishing that can obtained through application of various chemicals with different mechanisms of actions. In this paper, a novel mothproofing method is introduced through treatment of wool fabric with nano titanium dioxide (NTO) and citric acid (CA). Citric acid (CA) helps to enhance the washing durability, antifelting, and antibacterial properties of the NTO treated wool. Mothproofing was assessed through the study of damages on the wool surface by the larvae of the carpet beetle, Anthrenus verbasci, feeding on protein fibers. The damage intensity of wool fabric and TiO2 nanoparticles on the fabric surface were confirmed with scanning electron microscopy images and energy-dispersive spectrometry. X-ray diffraction (XRD) of NTO treated fabrics indicated the crystal structure of NTO on the wool surface. Overall, the wool fabrics treated with CA and NTO indicated the highest protection against moths compared with raw and bleached wool fabrics.