CNT-Al2O3 nanoparticle suspensions without and with sodium dodecyl sulfate (SDS) were freeze-cast into green samples. SDS drastically improves Carbon nanotube (CNT) dispersion and CNT-Al2O3 nanocomposite homogeneity. Green density of the CNT-Al2O3 nanocomposites decreases with CNT addition. Green strength of the CNT-Al2O3 nanocomposites increases with the CNT content when CNTs are well separated. The CNT-Al2O3 nanocomposites show medium energy fracture mode during equibiaxial flexural strength testing and change color in response to CNT content and distribution in the Al2O3 nanoparticle matrix.