The interlaminar shear strengths of nanostitched 3D aramid/phenolic composites were studied. Stitching slightly improved the interlaminar strength of the z-stitching/nanotube composites. In addition, the stitching fiber type influenced the interlaminar strength of the z-stitching/nanotube aramid/phenolic composites. The failures of all structures in the compression and tensile sides were almost negligible. However, all structures had interlaminar shear failure where delamination in z-stitching/nanotube composites was arrested. The introduction of the stitching yarn in the baseline structure improved its out-of-plane failure properties without reducing the in-plane properties. The effects of stitching and multiwall carbon nanotubes on the 3D aramid/phenolic composite were encouraging and the nanostitched para-aramid/phenolic nanocomposite could be considered as damage tolerance material.