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A new ceramic–carbon nanostructured hybrid (86vol.% ceramics, 14vol.% carbon) formed from organoclay during pyrolysis is reported. It functions as a reinforcing filler and a binder for carbon/carbon (C/C) composites. Alone, it can also serve as a high-temperature structural monolith. During pyrolysis, the ordered montmorillonite clay (d 001 31.5Å) is transformed to mullite, cristobalite and disordered clay, allowing the clay part of the organoclay to serve as both binder and reinforcement. The organic part serves as a binder. Thus, a unidirectional C/C composite (50vol.% fibers, 33vol.% carbon matrix, 5vol.% hybrid and 12% porosity) exhibiting flexural strength 290MPa, modulus 55GPa and toughness 2.9MPa is obtained by 1000°C 21-MPa hot-press pyrolysis in the presence of mesophase pitch powder, which serves as an additional binder, without densification after the pyrolysis. With the hybrid incorporation, the fiber content decreases from 53 to 50vol.%, but the flexural strength and modulus are increased by 46% and 14% respectively, relative to the composite without the hybrid but with densification. Hot pressing the organoclay alone forms a black monolithic sheet with high thermal stability, electrical resistivity 6×106 Ωcm, flexural strength 180MPa, modulus 69GPa, but low ductility. [ABSTRACT FROM AUTHOR]