The influence of rotation on the unimolecular dissociation of HN2 and DN2 is investigated. The semiclassical method we have been using for treating tunneling within classical trajectory simulations is employed to compute the level widths of selected states in both low and high energy regions. The rotational motion is considered by assigning different rotational energies and orientations of the angular momentum. It is found that the level widths for many of the states studied depend strongly on the magnitude and orientation of the angular momentum, and the variation is more pronounced in the low-energy tunneling regime. (C) 2003 American Institute of Physics.