Yew trees are used in the Woodcutting Skill to obtain Yew logs. They can be cut down at 60 Woodcutting granting 175 experience per log. The logs can be burned at level 60 Firemaking granting 202.5 xp. They can be Fletched into a Yew shortbow (u), a Yew longbow (u), or a Yew stock. It is currently the highest level tree for free players, thus resulting in high popularity in free worlds.
Yew trees can be farmed from a Yew seed at level 60 Farming. This can be done by placing a yew seed into a plant pot and watering it, and waiting for it to grow into a sapling. It can then be planted into a cleared tree patch.
Note: Any kind of trees you build in your house will not be able to be cut down.