  In this paper we study the integrability of 3-d Bohmian trajectories of a
system of quantum harmonic oscillators. We show that the initial choice of
quantum numbers is responsible for the existence (or not) of an integral of
motion which confines the trajectories on certain invariant surfaces. We give a
few examples of orbits in cases where there is or there is not an integral and
make some comments on the impact of partial integrability in Bohmian Mechanics.
Finally, we make a connection between our present results for the integrability
in the 3-d case and analogous results found in the 2-d and 4-d cases.
