The effect of nitrogen plasma on the morphology and properties of tasar silk fibers and fabrics has been investigated. The changes in the morphological structure were studied using the techniques of transmission electron microscopy, scanning electron microscopy, x-ray diffraction, and infrared spectroscopy. The changes in some textile properties, such as wettability, drying rate, and crease recovery, as a result of plasma treatment, were also studied. It was found that the plasma treatment is effective only on the surface of the fibers and fabrics. Wettability increased and the drying rate became faster due to the treatment; however, the crease-recovery angle decreased. The results were used to arrive at an understanding regarding the internal structure of tasar silk.