Different approaches for the functional finishing of textile are now assessed as the popular subjects. In this respect wool fabrics were dyed with the leaves of oak and acorn (the different parts of the oak tree). The dyeing processes were carried out by using different mordants in different mordanting-dyeing processes. The samples were then investigated in terms of the obtained colors, fastness values, and UV protection features. It was observed that by use of acorn and oak leaves, the wool fabrics can be colored even when the mordanting agents were not used. In that case, the fastness values to washing, rubbing, and light were perfect too. Addition of the different mordanting agents caused different colors. Generally brown colors in different shades were obtained during the studies and the mordanting method was also found as responsible for the differences in obtained colors. Meanwhile, it was observed that the undyed wool has exhibited an UV protection feature but by using different natural dye sources, the UV protection feature of the fabrics was significantly increased. It was also found that UV protection properties of the fabrics increased with only mordants (without dyeing) as well.