The spin and the orbital angular momentums of multiple surface-plasmon-polariton (SPP) waves guided by a planar interface of a metal and a periodically nonhomogeneous sculptured nematic thin film (SNTF) were theoretically investigated in the canonical boundary-value problem. Both the Minkowski and the Abraham formulations of angular momentums were considered. Multiple SPP waves guided by the metal/SNTF interface in a direction obliquely with respect to the morphologically significant plane of the SNTF were found to have different magnitudes and directions of the spin and the orbital angular momentums. The spin angular momentum is oriented in a variety of directions, but the orbital angular momentum is perpendicular to the direction of propagation and lies in the interface plane. Not only does the periodic nonhomogeneity of the partnering dielectric material engender a multiplicity of SPP waves, but it can also enhance the magnitudes of the spin and orbital components of their angular momentums. ii