The diffusion of benzene in the high silica zeolite ZSM5 has been studied at various coverages by pulsed field gradient nuclear magnetic resonance (PFGNMR) and quasi-elastic neutron scattering (QUENS). The PFGNMR technique has probed inter- and intra-crystalline diffusion over the millisecond timescale giving intra coefficients of the order 10-10 m2 s-1 and inter coefficients in the range from 10-7 to 10-9 m2 s-1 with increasing coverage. This suggests a 'viscous' liquid-like environment inside the zeolite but rather faster diffusion between crystallites. QUENS has probed intra-crystalline diffusion on the nanosecond timescale giving results in the range 10-10 to 10-9 m2 s-1 at high coverages. A jump activation energy for this process of 5.0 ± 0.4 kJ mol-1 has been estimated over the temperature range of 213 to 343 K.