The purposeful incorporation of mesopores has become an important issue of the synthesis and post-synthesis modification of nanoporous solids for generating transport-optimized materials. The potentials of the pulsed field gradient (PFG) technique of NMR for assessing the transport properties of such materials are discusses and first case studies demonstrating the spectrum of information provided by the application of this technique to diffusion studies in hierarchical porous materials and the still existing limitations are presented.