  We provide a description of the structure of $\aleph_0$-categorical trees and
cycle-free partial orders. First the maximal branches of $\aleph_0$-categorical
tree are examined, followed by the configuration of the ramification orders,
which are then combined to provided necessary and sufficient conditions for a
tree to be $\aleph_0$-categorical in terms of these two things. The
classification of the $\aleph_0$-categorical cycle-free partial orders is found
as a corollary.
