The property enhancements associated with dispersion of nanoparticles in polymers will depend not only on the state of dispersion achieved during the synthesis or formulation of the nanocomposite, but also on the degree and direction of particle alignment induced during subsequent processing. Here we present data on flow-induced orientation in two classes of nanoparticle dispersions, based on multi-walled carbon nanotubes (MWNTs) and organically modified clay. Particles are dispersed in viscous but Newtonian matrices (uncured epoxy resin and oligomeric polybutene, respectively) to allow focus on the fundamentals of flow-induced particle orientation free from complications associated with polymer melt viscoelasticity. Small- and wide-angle x-ray scattering under shear are used to probe flow-induced anisotropy in the particle orientation distribution. Both samples show particle alignment increasing with shear rate. In dilute MWNT dispersions, flow-induced alignment is correlated with break-down of large aggregates. In more concentrated dispersion, unexpected rapid relaxation of flow-induced alignment suggests that some of the observed alignment stems from elastic distortion of entangled nanotubes within clusters. In the clay dispersions, attempts are made to explore the relationship between particle orientation and bulk rheological behavior. In both systems, we have explored the relation between anisotropy measures extracted from small- and wide-angle x-ray scattering, which probe fluid structure at different length scales.