Processes for converting C8 aromatic hydrocarbons. In some embodiments, the process can include feeding a gaseous hydrocarbon feed that can include meta-xylene, ortho-xylene, or both into a conversion zone. The process can also include contacting the gaseous hydrocarbon feed with a catalyst that can include a ZSM-11 zeolite in the conversion zone under conversion conditions to effect isomerization of at least a portion of any meta-xylene, or at least a portion of any ortho-xylene, or both to produce a conversion product rich in para-xylene. In some embodiments, the ZSM-11 zeolite can have an alpha value of 1 to 3,000 and a molar ratio of silica to alumina of from 15 to 200.