Let $P$ be a partially ordered set (poset). The main objective of the present paper is to introduce and study the idea of permuting tri-derivations of posets. Several characterization theorems involving permuting tri-derivations are given. In particular, we prove that if $d_1$ and $d_2$ are two permuting tri-derivations of $P$ with traces $\phi_1$ and $\phi_2,$ then $\phi_1 \leq \phi_2 $ if and only if $\phi_{2}(\phi_{1}(x)) =\phi_1(x)$ for all $x\in P$.